Other Rare Childhood Cancers
Multiple Endocrine Neoplasia (MEN) Syndromes and Carney Complex
Clinical presentation and diagnostic evaluation of MEN syndromes
Treatment of MEN syndromes
Pheochromocytoma and Paraganglioma
Paraganglioma and pheochromocytoma in children and adolescents
Skin Cancer (Melanoma, Basal Cell Carcinoma, and Squamous Cell Carcinoma)
Basal cell and squamous cell carcinomas
Cancer of Unknown Primary Site
Other rare childhood cancers include multiple endocrine neoplasia syndromes and Carney complex, skin cancer, chordoma, and cancer of unknown primary site. The prognosis, diagnosis, classification, and treatment of these other rare childhood cancers are discussed below. It must be emphasized that these cancers are seen very infrequently in patients younger than 15 years, and most of the evidence is derived from case series.Multiple Endocrine Neoplasia (MEN) Syndromes and Carney Complex
MEN syndromes are familial disorders that are characterized by neoplastic changes that affect multiple endocrine organs. Changes may include hyperplasia, benign adenomas, and carcinomas. There are two main types of MEN syndrome: type 1 and type 2. MEN type 2 can be further subdivided into three subtypes: type 2A, type 2B, and familial medullary thyroid carcinoma. (Refer to the PDQ summary on Genetics of Endocrine and Neuroendocrine Neoplasias for more information about MEN syndromes.)Clinical presentation and diagnostic evaluation of MEN syndromes
The most salient clinical and genetic alterations of the MEN syndromes are shown in Table 5.Table 5. MEN Syndromes with Associated Clinical and Genetic Alterations
|Syndrome||Clinical Features/Tumors||Genetic Alterations|
|MEN type 1: Werner syndrome ||Parathyroid||11q13 (MEN1 gene)|
|Pancreatic islets:||Gastrinoma||11q13 (MEN1 gene)|
|Pituitary:||Prolactinoma||11q13 (MEN1 gene)|
|Other associated tumors:||Carcinoid: bronchial and thymic||11q13 (MEN1 gene)|
|MEN type 2A: Sipple syndrome||Medullary thyroid carcinoma||10q11.2 (RET gene)|
|MEN type 2B||Medullary thyroid carcinoma||10q11.2 (RET gene)|
|Familial medullary thyroid carcinoma||Medullary thyroid carcinoma||10q11.2 (RET gene)|
- MEN 1 syndrome: MEN 1 syndrome, also referred to as Werner syndrome, is an autosomal dominant disorder characterized by the presence of tumors in the parathyroid, pancreatic islet cells, and anterior pituitary. Diagnosis of this syndrome should be considered when two of the three endocrine tumors listed in the table above are present. Less common tumors associated with this syndrome include adrenocortical tumors, carcinoid tumors, lipomas, angiofibromas, and collagenomas. The first manifestation of the disease in 90% of patients is hypercalcemia; the most common cause of morbidity and mortality in these patients is the development of gastrinomas, leading to Zollinger-Ellison syndrome.[2,3]
Germline mutations of the MEN1 gene located on chromosome 11q13 are found in 70% to 90% of patients; however, this gene has also been shown to be frequently inactivated in sporadic tumors. Mutation testing should be combined with clinical screening for patients and family members with proven at-risk MEN 1 syndrome. It is recommended that screening for patients with MEN 1 syndrome begin by the age of 5 years and continue for life. The number of tests or biochemical screening is age specific and may include yearly serum calcium, parathyroid hormone, gastrin, glucagon, secretin, proinsulin, chromogranin A, prolactin, and IGF-1. Radiologic screening should include a magnetic resonance imaging of the brain and computed tomography (CT) of the abdomen every 1 to 3 years.
- MEN 2A and 2B syndromes:
A germline activating mutation in the RET oncogene (a receptor tyrosine kinase) on chromosome 10q11.2 is responsible for the uncontrolled growth of cells in medullary thyroid carcinoma associated with MEN 2A and MEN 2B syndromes.[7-9]
- MEN 2A is characterized by the presence of two or more endocrine tumors (see Table 6) in an individual or in close relatives. RET mutations in these patients are usually confined to exons 10 and 11.
- MEN 2B is characterized by medullary thyroid carcinomas, parathyroid hyperplasias, adenomas, pheochromocytomas, mucosal neuromas, and ganglioneuromas.[10-12] The medullary thyroid carcinomas that develop in these patients are extremely aggressive. More than 95% of mutations in these patients are confined to codon 918 in exon 16, causing receptor autophosphorylation and activation. Patients also have medullated corneal nerve fibers, distinctive faces with enlarged lips, and an asthenic Marfanoid body habitus. A pentagastrin stimulation test can be used to detect the presence of medullary thyroid carcinoma in such patients, although management of patients is driven primarily by the results of genetic analysis for RET mutations.[13,14]
Guidelines for genetic testing of suspected patients with MEN2 syndrome and the correlations between the type of mutation and the risk levels of aggressiveness of medullary thyroid cancer, have been published.[14,15]
- Familial Medullary Thyroid Carcinoma: Familial medullary thyroid carcinoma is diagnosed in families with medullary thyroid carcinoma in the absence of pheochromocytoma or parathyroid adenoma/hyperplasia. RET mutations in exons 10, 11, 13, and 14 account for most cases. (See Table 6.)
|MEN 2 Subtype||Medullary Thyroid Carcinoma||Pheochromocytoma||Parathyroid Disease|
|MEN 2A||95%||50%||20% to 30%|
|Familial medullary thyroid carcinoma||100%||0%||0%|
Treatment of MEN syndromes
- MEN 1 syndrome: Treatment of patients with MEN 1 syndrome is based on the type of tumor. The outcome of patients with the MEN 1 syndrome is generally good provided adequate treatment can be obtained for parathyroid, pancreatic, and pituitary tumors.
- MEN 2 syndromes: The management of medullary thyroid cancer in children from families having the MEN 2 syndromes relies on presymptomatic detection of the RET proto-oncogene mutation responsible for the disease.
- MEN 2A syndrome: For children with MEN 2A, thyroidectomy is commonly performed by approximately age 5 years or older if that is when a mutation is identified. [9,16-20] The outcome for patients with the MEN 2A syndrome is also generally good, yet the possibility exists for recurrence of medullary thyroid carcinoma and pheochromocytoma.[21-23]
Relatives of patients with MEN 2A should undergo genetic testing in early childhood, before the age of 5 years. Carriers should undergo total thyroidectomy as described above with autotransplantation of one parathyroid gland by a certain age.[20,24-26]
- MEN 2B syndrome: Because of the increased virulence of medullary thyroid carcinoma in children with MEN 2B and in those with mutations in codons 883, 918, and 922, it is recommended that these children undergo prophylactic thyroidectomy in infancy.[13,17,27]; [Level of evidence: 3iiiDii] Patients who have the MEN 2B syndrome have a worse outcome primarily due to more aggressive medullary thyroid carcinoma. Prophylactic thyroidectomy has the potential to improve the outcome in MEN 2B, but there are no long-term outcome reports published to date.
Complete removal of the thyroid gland is the recommended procedure for surgical management of medullary thyroid cancer in children, since there is a high incidence of bilateral disease.
Hirschsprung disease has been associated in a small percentage of cases with the development of neuroendocrine tumors such as medullary thyroid carcinoma. RET germline inactivating mutations have been detected in up to 50% of patients with familial Hirschsprung disease and less often in the sporadic form.[29-31] Cosegregation of Hirschsprung disease and medullary thyroid carcinoma phenotype is infrequently reported, but these individuals usually have a mutation in RET exon 10. It has been recommended that patients with Hirschsprung disease be screened for mutations in RET exon 10 and consideration be given to prophylactic thyroidectomy if such a mutation is discovered.[31-33]
(Refer to the PDQ summary on Genetics of Endocrine and Neuroendocrine Neoplasias for more information about MEN 2A and MEN 2B.)
- MEN 2A syndrome: For children with MEN 2A, thyroidectomy is commonly performed by approximately age 5 years or older if that is when a mutation is identified. [9,16-20] The outcome for patients with the MEN 2A syndrome is also generally good, yet the possibility exists for recurrence of medullary thyroid carcinoma and pheochromocytoma.[21-23]
In a randomized phase III trial for adult patients with unresectable locally advanced or metastatic hereditary or sporadic medullary thyroid carcinoma treated with vandetanib, a selective inhibitor of RET, VEGFR, and EGFR, versus placebo, vandetanib administration was associated with significant improvements in progression-free survival, response rate, disease control rates, and biochemical response.Treatment options under clinical evaluation
The following is an example of a national and/or institutional clinical trial that is currently being conducted. Information about ongoing clinical trials is available from the NCI Web site.
- NCI-07-C-0189 (NCT00514046) (Vandetanib to Treat Children and Adolescents With Medullary Thyroid Cancer): This phase I/II NCI trial is investigating vandetanib, an orally available tyrosine kinase receptor inhibitor, for patients aged 5 to 18 years, with hereditary thyroid medullary carcinoma.[35,36]
The Carney complex is an autosomal dominant syndrome caused by mutations in the PPKAR1A gene, located in chromosome 17. The syndrome is characterized by cardiac and cutaneous myxomas, pale brown to brown lentigines, blue nevi, primary pigmented nodular adrenocortical disease causing Cushing syndrome, and a variety of endocrine and nonendocrine tumors, including pituitary adenomas, thyroid tumors, and large cell calcifying Sertoli cell tumor of the testis.[37-39] There are guidelines that may be followed for screening patients with Carney complex.
For patients with the Carney complex, prognosis depends on the frequency of recurrences of cardiac and skin myxomas and other tumors.Pheochromocytoma and Paraganglioma
Pheochromocytoma and paraganglioma are rare catecholamine-producing tumors with a combined annual incidence of three cases per 1 million individuals. Tumors arising within the adrenal gland are known as pheochromocytomas, whereas morphologically identical tumors arising elsewhere are termed paragangliomas. Paragangliomas are further divided into: (1) sympathetic paragangliomas that predominantly arise from the intra-abdominal sympathetic trunk and usually produce catecholamines, and (2) parasympathetic paragangliomas that are distributed along the parasympathetic nerves of the head, neck, and mediastinum and are rarely functional.[40,41]Genetic predisposition
It is now estimated that up to 30% of all pheochromocytomas and paragangliomas are familial; several susceptibility genes have been described (see Table 7). The median age at presentation in most familial syndromes is 30 to 35 years, and up to 50% of subjects have disease by age 26 years.[42-45]Table 7. Characteristics of Paraganglioma (PGL) and Pheochromocytoma (PCC) Associated with Susceptibility Genesa
|Germline Mutation||Syndrome||Proportion of all PGL/PCC (%)||Mean Age at Presentation (y)||Penetrance of PGL/PCC (%)|
|SDHB, C, D||Carney-Stratakis||<1||33||Unknown|
|No mutation||Sporadic disease||70||48.3||-|
|MEN1 = multiple endocrine neoplasia type 1; MEN2 = multiple endocrine neoplasia type 2; NF1 = neurofibromatosis type 1; VHL = von Hippel-Lindau.|
|aAdapted from Welander et al.|
- Von Hippel-Lindau (VHL) syndrome—Pheochromocytoma and paraganglioma occur in 10% to 20% of patients with VHL.
- Multiple Endocrine Neoplasia (MEN) Syndrome Type 2—Codon-specific mutations of the RET gene are associated with a 50% risk of development of pheochromocytoma in MEN 2A and MEN 2B. Somatic RET mutations are also found in sporadic pheochromocytoma and paraganglioma.
- Neurofibromatosis type 1 (NF1)—Pheochromocytoma and paraganglioma are a rare occurrence in patients with NF1, and typically have characteristics similar to those of sporadic tumors, with a relatively late mean age of onset and rarity in pediatrics.
- Familial pheochromocytoma/paraganglioma syndromes, associated with germline mutations of mitochondrial succinate dehydrogenase (SDH) complex genes (see Table 7). They are all inherited in an autosomal dominant manner but with varying penetrance.
- PGL1—Associated with SDHD mutations, manifests more commonly with head and neck paragangliomas, and has a very high penetrance, with more than 80% of carriers developing disease by age 50 years.
- PGL2—Associated with SDHAF2 mutations, is very rare, and generally manifests as parasympathetic paraganglioma.
- PGL3—Associated with SDHC mutations, is very rare, and usually presents with parasympathetic paraganglioma, often unifocal, benign, and in the head and neck location.
- PGL4—Associated with SDHB mutations and usually manifests with intra-abdominal sympathetic paraganglioma. The neoplasms associated with this mutation have a much higher risk of malignant behavior, with more than 50% of patients developing metastatic disease. There is also an increased risk of renal cell carcinoma and gastrointestinal stromal tumor (GIST).
- Other susceptibility genes recently discovered include KIF1B-beta, EGLN1/PHD2, TMEM127, SDHA, and MAX.
- Other syndromes:
- Carney triad syndrome is a condition that includes three tumors: paraganglioma, GIST, and pulmonary chondromas. Pheochromocytomas and other lesions such as esophageal leiomyomas and adrenocortical adenomas have also been described. The syndrome primarily affects young women, with a mean age of 21 years at time of presentation. Approximately one-half of the patients present with paraganglioma or pheochromocytoma, although multiple lesions occur in approximately only 20% of the cases. About 20% of the patients have all three tumor types; the remainder have two of the three, most commonly GIST and pulmonary chondromas. This triad doesn’t appear to run in families and no responsible gene has been discovered.
- Carney-Stratakis syndrome (Carney dyad syndrome) is a condition that includes paraganglioma and GIST, but no pulmonary chondromas. It is inherited in an autosomal dominant manner with incomplete penetrance. It is equally common in men and women, with an average age of 23 years at presentation. The majority of patients with this syndrome have been found to carry germline mutations in the SDHB, SDHC, or SDHD genes.
Immunohistochemical SDHB staining may help triage genetic testing; tumors of patients with SDHB, SDHC, and SDHD mutations have absent or very weak staining, while sporadic tumors and those associated with other constitutional syndromes have positive staining.[47,48] Therefore, immunohistochemical SDHB staining can help identify potential carriers of a SDH mutation early, thus obviating the need for extensive and costly testing of other genes.Clinical presentation
Patients with pheochromocytoma and sympathetic extra-adrenal paraganglioma usually present with symptoms of excess catecholamine production, including hypertension, headache, perspiration, palpitations, tremor, and facial pallor. These symptoms are often paroxysmal, although sustained hypertension between paroxysmal episodes occurs in more than one-half the patients. These symptoms can also be induced by exertion, trauma, labor and delivery, induction of anesthesia, surgery of the tumor, foods high in tyramine (e.g., red wine, chocolate, cheese), or urination (in cases of primary tumor of the bladder). Parasympathetic extra-adrenal paragangliomas do not secrete catecholamines and usually present as a neck mass with symptoms related to compression, but also may be asymptomatic and diagnosed incidentally.Paraganglioma and pheochromocytoma in children and adolescents
Younger patients have a higher incidence of bilateral adrenal pheochromocytoma and extra-adrenal paraganglioma, and a germline mutation can be identified in close to 60% of patients. Therefore, genetic counseling and testing is always recommended in young patients. The pediatric and adolescent patient appears to present with symptoms similar to those of the adult patient, although with a more frequent occurrence of sustained hypertension. The clinical behavior of paraganglioma and pheochromocytoma appears to be more aggressive in children and adolescents and metastatic rates of up to 50% have been reported.[41,50,51]
In a study of 49 patients younger than 20 years with a paraganglioma or pheochromocytoma, 39 (79%) had an underlying germline mutation that involved the SDHB (n = 27; 55%), SDHD (n = 4; 8%), VHL (n = 6; 12%), or NF1 (n = 2; 4%) genes. The germline mutation rates for patients with nonmetastatic disease were lower than those observed in patients who had evidence of metastases (64% vs. 87.5%). Furthermore, among patients with metastatic disease, the incidence of SDHB mutations was very high (72%) and most presented with disease in the retroperitoneum; five died of their disease. All patients with SDHD mutations had head and neck primary tumors. In another study, the incidence of germline mutations involving RET, VHL, SDHD and SDHB in patients with nonsyndromic paraganglioma was 70% for patients younger than 10 years and 51% among those aged 10 to 20 years. In contrast, only 16% of patients older than 20 years had an identifiable mutation. It is important to remember that these two studies did not include systematic screening for other genes that have been recently described in paraganglioma and pheochromocytoma syndromes such as KIF1B-beta, EGLN1/PHD2, TMEM127, SDHA, and MAX (see Table 7).
These findings suggest that younger patients with extra-adrenal nonsyndromic pheochromocytoma and paraganglioma are at high risk for harboring SDHB mutations and that this phenotype is associated with an earlier age of onset and a high rate of metastatic disease. Early identification of young patients with SDHB mutations using radiographic, serologic, and immunohistochemical markers could potentially decrease mortality and identify other family members who carry a germline SDHB mutation. In addition, approximately 12% of pediatric GIST patients have germline SDHB, SDHC, or SDHD mutations in the context of Carney-Stratakis syndrome.Diagnostic evaluation
The diagnosis of paraganglioma and pheochromocytoma relies on the biochemical documentation of excess catecholamine secretion coupled with imaging studies for localization and staging.Biochemical testing
Measurement of plasma-free fractionated metanephrines (metanephrine and normetanephrine) is usually the diagnostic tool of choice when the diagnosis of a secreting paraganglioma or pheochromocytoma is suspected. A 24-hour urine collection for catecholamines (epinephrine, norepinephrine, and dopamine) and fractionated metanephrines can also be performed for confirmation.
Catecholamine metabolic and secretory profiles are impacted by hereditary background; both hereditary and sporadic paraganglioma and pheochromocytoma differ markedly in tumor contents of catecholamines and corresponding plasma and urinary hormonal profiles. About 50% of secreting tumors produce and contain a mixture of norepinephrine and epinephrine, while most of the rest produce norepinephrine almost exclusively, with occasional rare tumors producing mainly dopamine. Patients with epinephrine-producing tumors are diagnosed later (median age, 50 years) than those with tumors lacking appreciable epinephrine production (median age, 40 years). Patients with MEN2 and NF1 syndromes, all with epinephrine-producing tumors, are typically diagnosed at a later age (median age, 40 years) than patients with tumors that lack appreciable epinephrine production secondary to mutations of VHL and SDH (median age, 30 years). These variations in ages at diagnosis associated with different tumor catecholamine phenotypes and locations suggest origins of paraganglioma and pheochromocytoma for different progenitor cells with variable susceptibility to disease-causing mutations.[54,55]Imaging
Imaging modalities available for the localization of paraganglioma and pheochromocytoma include CT, magnetic resonance imaging, iodine I-123 or iodine I-131–labeled metaiodobenzylguanidine (123/131I-mIBG) scintigraphy, and fluorine F-18 6-fluorodopamine (6-[18F]FDA) positron emission tomography (PET). For tumor localization, 6-[18F]FDA PET and 123/131I-mIBG scintigraphy perform equally well in patients with nonmetastatic paraganglioma and pheochromocytoma, but metastases are better detected by 6-[18F]FDA PET than by 123/131I-mIBG. Other functional imaging alternatives include indium In-111 octreotide scintigraphy and fluorodeoxyglucose F-18 PET, both of which can be coupled with CT imaging for improved anatomic detail.Treatment
Treatment of paraganglioma and pheochromocytoma is surgical. For secreting tumors, alpha and beta adrenergic blockade must be optimized prior to surgery. For patients with metastatic disease, responses have been documented to some chemotherapeutic regimens such as gemcitabine and docetaxel or vincristine, cyclophosphamide, and dacarbazine.[57,58] Chemotherapy may help alleviate symptoms and facilitate surgery, although its impact in overall survival is less clear. Responses have also been obtained to high-dose 131I-mIBG.Skin Cancer (Melanoma, Basal Cell Carcinoma, and Squamous Cell Carcinoma)
Melanoma, although rare, is the most common skin cancer in children, followed by basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs).[60-68] In a retrospective study of 22,524 skin pathology reports in patients younger than 20 years, investigators identified 38 melanomas, 33 of which occurred in patients aged 15 to 19 years. Study investigators reported that the number of lesions that needed to be excised in order to identify one melanoma was 479.8, which is 20 times higher than the adult population.
In patients younger than 20 years, there are approximately 425 cases of melanoma diagnosed each year in the United States, representing about 1% of all new cases of melanoma. Melanoma annual incidence in the United States (2002–2006) increases with age, from 1 to 2 per 1 million in children younger than 10 years to 4.1 per 1 million in children aged 10 to 14 years and 16.9 per 1 million in children aged 15 to 19 years. Melanoma accounts for about 8% of all cancers in children aged 15 to 19 years. The incidence of pediatric melanoma (in children younger than 20 years) increased by 1.7% per year between 1975 and 2006. Increased exposure to ambient ultraviolet radiation increases the risk of the disease.Risk factors
Conditions associated with an increased risk of developing melanoma in children and adolescents include giant melanocytic nevi, xeroderma pigmentosum (a rare recessive disorder characterized by extreme sensitivity to sunlight, keratosis, and various neurologic manifestations), immunodeficiency, immunosuppression, history of retinoblastoma, and Werner syndrome.[72,73] Other phenotypic traits that are associated with an increased risk of melanoma in adults have been documented in children and adolescents with melanoma and include exposure to ultraviolet sunlight, red hair, blue eyes,[74-78] poor tanning ability, freckling, dysplastic nevi, increased number of melanocytic nevi, and family history of melanoma.[79-81] Neurocutaneous melanosis is an unusual condition associated with large or multiple congenital nevi of the skin in association with meningeal melanosis or melanoma; approximately 2.5% of patients with large congenital nevi develop this condition, and those with increased numbers of satellite nevi are at greatest risk.[82,83]Prognosis
Pediatric melanoma shares many similarities with adult melanoma, and the prognosis is stage dependent. Overall 5-year survival of children and adolescents with melanoma is approximately 90%.[78,84,85] Approximately three-fourths of all children and adolescents present with localized disease and have an excellent outcome (>90% 5-year survival). The outcome for patients with nodal disease is intermediate, with about 60% expected to survive long term.[78,85] In one study, the outcome for patients with metastatic disease was favorable, but this result was not duplicated in another study from the National Cancer Database.
In pediatric melanoma, the association of thickness with clinical outcome is controversial.[78,85-88] In addition, pediatric melanoma appears to have a higher incidence of nodal involvement and this feature does not appear to have an impact on survival.[89,90] However, it is unclear how these findings truly affect clinical outcome since some series have included patients with atypical melanocytic lesions.[91,92] In a study of sentinel lymph node biopsies in children and adolescents, 25% were positive (compared with 17% in adults). However, only 0.7% of lymph nodes found on complete lymph node dissection were positive for melanoma. In this study, mortality was infrequent but was confined to sentinel lymph node–positive patients.[Level of evidence: 3iiA] In another study, 53% of patients younger than 10 years had positive sentinel lymph node biopsy compared with 26% of those who were aged 10 years and older.
Children younger than 10 years who have melanoma often present with poor prognostic features, are more often non-white, have head and neck primary tumors, and more often have syndromes that predispose them to melanoma.[78,84,85,94]Diagnostic evaluation
Biopsy or excision is necessary to determine the diagnosis of any skin cancer. Diagnosis is necessary for decisions regarding additional treatment. Although BCCs and SCCs are generally curable with surgery alone, the treatment of melanoma requires greater consideration because of its potential for metastasis. The width of surgical margins in melanoma is dictated by the site, size, and thickness of the lesion and ranges from 0.5 cm for in situ lesions to 2 cm or more for thicker lesions. To achieve negative margins in children, wide excision with skin grafting may become necessary in selected cases. Examination of regional lymph nodes using sentinel lymph node biopsy has become routine in many centers [95,96] and is recommended in patients with lesions measuring more than 1 mm in thickness or in those whose lesions are 1 mm or less in thickness and have unfavorable features such as ulceration, Clark level of invasion IV or V, or mitosis rate of 1 per mm2 or higher.[95,97,98]
Lymph node dissection is recommended if sentinel nodes are involved with tumor, and adjuvant therapy with high-dose interferon-alpha-2b for a period of 1 year should be considered in these patients.[64,95,99-101] Clinically benign melanocytic lesions can sometimes pose a significant diagnostic challenge, especially when they involve regional lymph nodes.[102-104]
The diagnosis of pediatric melanoma may be difficult and many of these lesions may be confused with the so-called melanocytic tumors of unknown metastatic potential. These lesions are biologically different from melanoma and benign nevi.[105,106] The term Spitz nevus and Spitzoid melanoma are also commonly used, creating additional confusion. Novel diagnostic techniques are actively being used by various centers in an attempt to differentiate melanoma from these challenging melanocytic lesions. For example, the absence of BRAF mutations or the presence of a normal chromosomal complement with or without 11p gains strongly argues against the diagnosis of melanoma.[107,108] In contrast, the use of FISH probes that target four specific regions in chromosomes 6 and 11 can help classify melanoma correctly in over 85% of cases; however, 24% of atypical Spitzoid lesions will have chromosomal alterations on FISH analysis and 75% will have BRAF V600E mutations.[109,110] HRAS mutations have been described in some cases of Spitz nevi but they have not been described in Spitzoid melanoma. The presence of a HRAS mutation may aid in the differential diagnosis of Spitz nevus and Spitzoid melanoma. Some of the characteristic genetic alterations seen in various melanocytic lesions are summarized in the table below:[112,113]Table 8. Characteristics of Melanocytic Lesions
|Melanoma||BRAF, NRAS, KIT|
|Spitz nevus||HRAS; BRAF and NRAS (uncommon)|
|Dysplastic nevus||BRAF, NRAS|
|Congenital nevi||BRAF, NRAS|
Surgery is the treatment of choice for patients with localized melanoma. Current guidelines recommend margins of resection as follows:
- 0.5 cm for melanoma in situ.
- 1.0 cm for melanoma thickness under 1 mm.
- 1 cm to 2 cm for melanoma thickness of 1.01 mm to 2 mm.
- 2 cm for tumor thickness greater than 2 mm.
Sentinel node biopsy should be offered to patients with thin lesions (≤1 mm) and ulceration, mitotic rate greater than 1 mm2, young age, and to patients with lesions greater than 1 mm with or without adverse features. Young patients have a higher incidence of sentinel node positivity and this feature adversely affects clinical outcomes. If the sentinel node is positive, patients should be offered the option to undergo a complete lymph node dissection. Patients with high-risk primary cutaneous melanoma, such as those with regional lymph node involvement, should be offered the option to receive adjuvant interferon alpha-2b, a therapy that is well tolerated in children.[99,100,115]
For patients with metastatic disease, prognosis is poor and various agents such as interferon, dacarbazine, temozolomide, sorafenib, or interleukin-2, and biochemotherapy can be used.[116-118] The results of pediatric trials that incorporate newer therapies such as vemurafenib and ipilimumab are not yet available.[119,120] Vemurafenib is used only in the treatment of patients with a BRAF mutation.
(Refer to the PDQ summary on adult Melanoma Treatment for more information.)Basal cell and squamous cell carcinomas
Basal cell carcinomas (BCCs) generally appear as raised lumps or ulcerated lesions, usually in areas with previous sun exposure. These tumors may be multiple and exacerbated by radiation therapy. Nevoid BCC syndrome (Gorlin syndrome) is a rare disorder with a predisposition to the development of early-onset neoplasms, including BCC, ovarian fibroma, and desmoplastic medulloblastoma.[123-126] SCCs are usually reddened lesions with varying degrees of scaling or crusting, and they have an appearance similar to eczema, infections, trauma, or psoriasis.Diagnostic evaluation and treatment
Biopsy or excision is necessary to determine the diagnosis of any skin cancer. Diagnosis is necessary for decisions regarding additional treatment. BCCs and SCCs are generally curable with surgery alone and further diagnostic workup is not indicated.
Most BCCs have activation of the hedgehog pathway, generally resulting from mutations in PTCH1. Vismodegib (GDC-0449), a hedgehog pathway inhibitor, has been approved for the treatment of adult patients with BCC.[128,129] It was approved by the U.S. Food and Drug Administration for the treatment of adults with metastatic BCC or with locally advanced BCC that has recurred following surgery or who are not candidates for surgery, and who are not candidates for radiation. This drug also reduces the tumor burden in patients with basal cell nevus syndrome.
(Refer to the PDQ summary on adult Skin Cancer Treatment for more information.)Chordoma
Chordoma is a very rare tumor of bone that arises from remnants of the notochord within the clivus, spinal vertebrae, or sacrum. The incidence in the United States is approximately one case per one million people per year, and only 5% of all chordomas occur in patients younger than 20 years. Most pediatric patients have the conventional or chondroid variant of chordoma.[131,132]Prognosis Clinical presentation
Patients usually present with pain, with or without neurologic deficits such as cranial or other nerve impairment. Diagnosis is straightforward when the typical physaliferous (soap-bubble-bearing) cells are present. Differential diagnosis is sometimes difficult and includes dedifferentiated chordoma and chondrosarcoma. Childhood chordoma has been associated with tuberous sclerosis complex.Treatment
Standard treatment includes surgery and external radiation therapy, often proton-beam radiation. Surgery is not commonly curative in children and adolescents because of difficulty obtaining clear margins and the likelihood of the chordoma arising in the skull base, rather than in the sacrum, making them relatively inaccessible to complete surgical excision. The best results have been obtained using proton-beam therapy (charged-particle radiation therapy).[138,139]; [Level of evidence: 3iiA]; [Level of evidence: 3iiiDiii]
There is no known effective cytotoxic agent or combination chemotherapy for this disease, with only anecdotal reports published. Imatinib mesylate has been studied in adults with chordoma on the basis of the overexpression of PDGFR alpha, beta, and KIT in this disease.[141,142] Among 50 adults with chordoma treated with imatinib and evaluable by RECIST, there was one partial response and 28 additional patients had stable disease at 6 months. The low rate of RECIST responses and the potentially slow natural course of the disease complicate the assessment of the efficacy of imatinib for chordoma. Other tyrosine kinase inhibitors and combinations involving kinase inhibitors have been studied.[143-145]
Recurrences are usually local but can include distant metastases to lungs or bone.Cancer of Unknown Primary Site
Cancers of unknown primary site present as a metastatic cancer for which a precise primary tumor site cannot be determined. As an example, lymph nodes at the base of the skull may enlarge in relationship to a tumor that may be on the face or the scalp but is not evident by physical examination or by radiographic imaging. Thus, modern imaging techniques may indicate the extent of the disease but not a primary site. Tumors such as adenocarcinomas, melanomas, and embryonal tumors such as rhabdomyosarcomas and neuroblastomas may have the above-mentioned presentation. Children represent less than 1% of all solid cancers of unknown primary site and because of the age-related incidence of tumor types, embryonal histologies are more common in this age group.Diagnostic evaluation
For all patients who present with tumors from an unknown primary site, treatment should be directed toward the specific histopathology of the tumor and should be age-appropriate for the general type of cancer initiated, irrespective of the site or sites of involvement. Studies in adults suggest that positron emission tomography (PET) imaging can be helpful in identifying cancers of unknown primary site, particularly in patients whose tumors arise in the head and neck area. A report in adults using fludeoxyglucose (FDG) PET-CT identified 42.5% of primary tumors in a group of cancers of unknown primary site. In addition, molecular assignment of tissue of origin using molecular profiling techniques is feasible and can aid in identifying the putative tissue of origin in about 60% of patients with cancers of unknown primary site. It is still unclear, however, whether these techniques can improve the outcomes or response rates of these patients, and no pediatric studies have been conducted.Treatment
Chemotherapy and radiation therapy treatments appropriate and relevant for the general category of carcinoma or sarcoma (depending on the histologic findings, symptoms, and extent of tumor) should be initiated as early as possible.References
- de Krijger RR: Endocrine tumor syndromes in infancy and childhood. Endocr Pathol 15 (3): 223-6, 2004. [PUBMED Abstract]
- Thakker RV: Multiple endocrine neoplasia--syndromes of the twentieth century. J Clin Endocrinol Metab 83 (8): 2617-20, 1998. [PUBMED Abstract]
- Starker LF, Carling T: Molecular genetics of gastroenteropancreatic neuroendocrine tumors. Curr Opin Oncol 21 (1): 29-33, 2009. [PUBMED Abstract]
- Farnebo F, Teh BT, Kytölä S, et al.: Alterations of the MEN1 gene in sporadic parathyroid tumors. J Clin Endocrinol Metab 83 (8): 2627-30, 1998. [PUBMED Abstract]
- Field M, Shanley S, Kirk J: Inherited cancer susceptibility syndromes in paediatric practice. J Paediatr Child Health 43 (4): 219-29, 2007. [PUBMED Abstract]
- Thakker RV: Multiple endocrine neoplasia type 1 (MEN1). Best Pract Res Clin Endocrinol Metab 24 (3): 355-70, 2010. [PUBMED Abstract]
- Sanso GE, Domene HM, Garcia R, et al.: Very early detection of RET proto-oncogene mutation is crucial for preventive thyroidectomy in multiple endocrine neoplasia type 2 children: presence of C-cell malignant disease in asymptomatic carriers. Cancer 94 (2): 323-30, 2002. [PUBMED Abstract]
- Alsanea O, Clark OH: Familial thyroid cancer. Curr Opin Oncol 13 (1): 44-51, 2001. [PUBMED Abstract]
- Fitze G: Management of patients with hereditary medullary thyroid carcinoma. Eur J Pediatr Surg 14 (6): 375-83, 2004. [PUBMED Abstract]
- Puñales MK, da Rocha AP, Meotti C, et al.: Clinical and oncological features of children and young adults with multiple endocrine neoplasia type 2A. Thyroid 18 (12): 1261-8, 2008. [PUBMED Abstract]
- Skinner MA, DeBenedetti MK, Moley JF, et al.: Medullary thyroid carcinoma in children with multiple endocrine neoplasia types 2A and 2B. J Pediatr Surg 31 (1): 177-81; discussion 181-2, 1996. [PUBMED Abstract]
- Brauckhoff M, Gimm O, Weiss CL, et al.: Multiple endocrine neoplasia 2B syndrome due to codon 918 mutation: clinical manifestation and course in early and late onset disease. World J Surg 28 (12): 1305-11, 2004. [PUBMED Abstract]
- Sakorafas GH, Friess H, Peros G: The genetic basis of hereditary medullary thyroid cancer: clinical implications for the surgeon, with a particular emphasis on the role of prophylactic thyroidectomy. Endocr Relat Cancer 15 (4): 871-84, 2008. [PUBMED Abstract]
- Waguespack SG, Rich TA, Perrier ND, et al.: Management of medullary thyroid carcinoma and MEN2 syndromes in childhood. Nat Rev Endocrinol 7 (10): 596-607, 2011. [PUBMED Abstract]
- Kloos RT, Eng C, Evans DB, et al.: Medullary thyroid cancer: management guidelines of the American Thyroid Association. Thyroid 19 (6): 565-612, 2009. [PUBMED Abstract]
- Skinner MA, Moley JA, Dilley WG, et al.: Prophylactic thyroidectomy in multiple endocrine neoplasia type 2A. N Engl J Med 353 (11): 1105-13, 2005. [PUBMED Abstract]
- Skinner MA: Management of hereditary thyroid cancer in children. Surg Oncol 12 (2): 101-4, 2003. [PUBMED Abstract]
- Learoyd DL, Gosnell J, Elston MS, et al.: Experience of prophylactic thyroidectomy in multiple endocrine neoplasia type 2A kindreds with RET codon 804 mutations. Clin Endocrinol (Oxf) 63 (6): 636-41, 2005. [PUBMED Abstract]
- Guillem JG, Wood WC, Moley JF, et al.: ASCO/SSO review of current role of risk-reducing surgery in common hereditary cancer syndromes. J Clin Oncol 24 (28): 4642-60, 2006. [PUBMED Abstract]
- National Comprehensive Cancer Network.: NCCN Clinical Practice Guidelines in Oncology: Thyroid Carcinoma. Version 1.2011. Rockledge, Pa: National Comprehensive Cancer Network, 2011. Available online with free subscription. Last accessed June 07, 2013.
- Lallier M, St-Vil D, Giroux M, et al.: Prophylactic thyroidectomy for medullary thyroid carcinoma in gene carriers of MEN2 syndrome. J Pediatr Surg 33 (6): 846-8, 1998. [PUBMED Abstract]
- Dralle H, Gimm O, Simon D, et al.: Prophylactic thyroidectomy in 75 children and adolescents with hereditary medullary thyroid carcinoma: German and Austrian experience. World J Surg 22 (7): 744-50; discussion 750-1, 1998. [PUBMED Abstract]
- Skinner MA, Wells SA Jr: Medullary carcinoma of the thyroid gland and the MEN 2 syndromes. Semin Pediatr Surg 6 (3): 134-40, 1997. [PUBMED Abstract]
- Heizmann O, Haecker FM, Zumsteg U, et al.: Presymptomatic thyroidectomy in multiple endocrine neoplasia 2a. Eur J Surg Oncol 32 (1): 98-102, 2006. [PUBMED Abstract]
- Frank-Raue K, Buhr H, Dralle H, et al.: Long-term outcome in 46 gene carriers of hereditary medullary thyroid carcinoma after prophylactic thyroidectomy: impact of individual RET genotype. Eur J Endocrinol 155 (2): 229-36, 2006. [PUBMED Abstract]
- Piolat C, Dyon JF, Sturm N, et al.: Very early prophylactic thyroid surgery for infants with a mutation of the RET proto-oncogene at codon 634: evaluation of the implementation of international guidelines for MEN type 2 in a single centre. Clin Endocrinol (Oxf) 65 (1): 118-24, 2006. [PUBMED Abstract]
- Leboulleux S, Travagli JP, Caillou B, et al.: Medullary thyroid carcinoma as part of a multiple endocrine neoplasia type 2B syndrome: influence of the stage on the clinical course. Cancer 94 (1): 44-50, 2002. [PUBMED Abstract]
- Zenaty D, Aigrain Y, Peuchmaur M, et al.: Medullary thyroid carcinoma identified within the first year of life in children with hereditary multiple endocrine neoplasia type 2A (codon 634) and 2B. Eur J Endocrinol 160 (5): 807-13, 2009. [PUBMED Abstract]
- Decker RA, Peacock ML, Watson P: Hirschsprung disease in MEN 2A: increased spectrum of RET exon 10 genotypes and strong genotype-phenotype correlation. Hum Mol Genet 7 (1): 129-34, 1998. [PUBMED Abstract]
- Eng C, Clayton D, Schuffenecker I, et al.: The relationship between specific RET proto-oncogene mutations and disease phenotype in multiple endocrine neoplasia type 2. International RET mutation consortium analysis. JAMA 276 (19): 1575-9, 1996. [PUBMED Abstract]
- Fialkowski EA, DeBenedetti MK, Moley JF, et al.: RET proto-oncogene testing in infants presenting with Hirschsprung disease identifies 2 new multiple endocrine neoplasia 2A kindreds. J Pediatr Surg 43 (1): 188-90, 2008. [PUBMED Abstract]
- Skába R, Dvoráková S, Václavíková E, et al.: The risk of medullary thyroid carcinoma in patients with Hirschsprung's disease. Pediatr Surg Int 22 (12): 991-5, 2006. [PUBMED Abstract]
- Moore SW, Zaahl MG: Multiple endocrine neoplasia syndromes, children, Hirschsprung's disease and RET. Pediatr Surg Int 24 (5): 521-30, 2008. [PUBMED Abstract]
- Wells SA Jr, Robinson BG, Gagel RF, et al.: Vandetanib in patients with locally advanced or metastatic medullary thyroid cancer: a randomized, double-blind phase III trial. J Clin Oncol 30 (2): 134-41, 2012. [PUBMED Abstract]
- Herbst RS, Heymach JV, O'Reilly MS, et al.: Vandetanib (ZD6474): an orally available receptor tyrosine kinase inhibitor that selectively targets pathways critical for tumor growth and angiogenesis. Expert Opin Investig Drugs 16 (2): 239-49, 2007. [PUBMED Abstract]
- Vidal M, Wells S, Ryan A, et al.: ZD6474 suppresses oncogenic RET isoforms in a Drosophila model for type 2 multiple endocrine neoplasia syndromes and papillary thyroid carcinoma. Cancer Res 65 (9): 3538-41, 2005. [PUBMED Abstract]
- Wilkes D, Charitakis K, Basson CT: Inherited disposition to cardiac myxoma development. Nat Rev Cancer 6 (2): 157-65, 2006. [PUBMED Abstract]
- Carney JA, Young WF: Primary pigmented nodular adrenocortical disease and its associated conditions. Endocrinologist 2: 6-21, 1992.
- Ryan MW, Cunningham S, Xiao SY: Maxillary sinus melanoma as the presenting feature of Carney complex. Int J Pediatr Otorhinolaryngol 72 (3): 405-8, 2008. [PUBMED Abstract]
- Lenders JW, Eisenhofer G, Mannelli M, et al.: Phaeochromocytoma. Lancet 366 (9486): 665-75, 2005 Aug 20-26. [PUBMED Abstract]
- Waguespack SG, Rich T, Grubbs E, et al.: A current review of the etiology, diagnosis, and treatment of pediatric pheochromocytoma and paraganglioma. J Clin Endocrinol Metab 95 (5): 2023-37, 2010. [PUBMED Abstract]
- Welander J, Söderkvist P, Gimm O: Genetics and clinical characteristics of hereditary pheochromocytomas and paragangliomas. Endocr Relat Cancer 18 (6): R253-76, 2011. [PUBMED Abstract]
- Timmers HJ, Gimenez-Roqueplo AP, Mannelli M, et al.: Clinical aspects of SDHx-related pheochromocytoma and paraganglioma. Endocr Relat Cancer 16 (2): 391-400, 2009. [PUBMED Abstract]
- Ricketts CJ, Forman JR, Rattenberry E, et al.: Tumor risks and genotype-phenotype-proteotype analysis in 358 patients with germline mutations in SDHB and SDHD. Hum Mutat 31 (1): 41-51, 2010. [PUBMED Abstract]
- Burnichon N, Cascón A, Schiavi F, et al.: MAX mutations cause hereditary and sporadic pheochromocytoma and paraganglioma. Clin Cancer Res 18 (10): 2828-37, 2012. [PUBMED Abstract]
- Stratakis CA, Carney JA: The triad of paragangliomas, gastric stromal tumours and pulmonary chondromas (Carney triad), and the dyad of paragangliomas and gastric stromal sarcomas (Carney-Stratakis syndrome): molecular genetics and clinical implications. J Intern Med 266 (1): 43-52, 2009. [PUBMED Abstract]
- Gill AJ, Benn DE, Chou A, et al.: Immunohistochemistry for SDHB triages genetic testing of SDHB, SDHC, and SDHD in paraganglioma-pheochromocytoma syndromes. Hum Pathol 41 (6): 805-14, 2010. [PUBMED Abstract]
- van Nederveen FH, Gaal J, Favier J, et al.: An immunohistochemical procedure to detect patients with paraganglioma and phaeochromocytoma with germline SDHB, SDHC, or SDHD gene mutations: a retrospective and prospective analysis. Lancet Oncol 10 (8): 764-71, 2009. [PUBMED Abstract]
- Barontini M, Levin G, Sanso G: Characteristics of pheochromocytoma in a 4- to 20-year-old population. Ann N Y Acad Sci 1073: 30-7, 2006. [PUBMED Abstract]
- King KS, Prodanov T, Kantorovich V, et al.: Metastatic pheochromocytoma/paraganglioma related to primary tumor development in childhood or adolescence: significant link to SDHB mutations. J Clin Oncol 29 (31): 4137-42, 2011. [PUBMED Abstract]
- Pham TH, Moir C, Thompson GB, et al.: Pheochromocytoma and paraganglioma in children: a review of medical and surgical management at a tertiary care center. Pediatrics 118 (3): 1109-17, 2006. [PUBMED Abstract]
- Neumann HP, Bausch B, McWhinney SR, et al.: Germ-line mutations in nonsyndromic pheochromocytoma. N Engl J Med 346 (19): 1459-66, 2002. [PUBMED Abstract]
- Lenders JW, Pacak K, Walther MM, et al.: Biochemical diagnosis of pheochromocytoma: which test is best? JAMA 287 (11): 1427-34, 2002. [PUBMED Abstract]
- Eisenhofer G, Pacak K, Huynh TT, et al.: Catecholamine metabolomic and secretory phenotypes in phaeochromocytoma. Endocr Relat Cancer 18 (1): 97-111, 2011. [PUBMED Abstract]
- Eisenhofer G, Timmers HJ, Lenders JW, et al.: Age at diagnosis of pheochromocytoma differs according to catecholamine phenotype and tumor location. J Clin Endocrinol Metab 96 (2): 375-84, 2011. [PUBMED Abstract]
- Timmers HJ, Chen CC, Carrasquillo JA, et al.: Comparison of 18F-fluoro-L-DOPA, 18F-fluoro-deoxyglucose, and 18F-fluorodopamine PET and 123I-MIBG scintigraphy in the localization of pheochromocytoma and paraganglioma. J Clin Endocrinol Metab 94 (12): 4757-67, 2009. [PUBMED Abstract]
- Mora J, Cruz O, Parareda A, et al.: Treatment of disseminated paraganglioma with gemcitabine and docetaxel. Pediatr Blood Cancer 53 (4): 663-5, 2009. [PUBMED Abstract]
- Huang H, Abraham J, Hung E, et al.: Treatment of malignant pheochromocytoma/paraganglioma with cyclophosphamide, vincristine, and dacarbazine: recommendation from a 22-year follow-up of 18 patients. Cancer 113 (8): 2020-8, 2008. [PUBMED Abstract]
- Gonias S, Goldsby R, Matthay KK, et al.: Phase II study of high-dose [131I]metaiodobenzylguanidine therapy for patients with metastatic pheochromocytoma and paraganglioma. J Clin Oncol 27 (25): 4162-8, 2009. [PUBMED Abstract]
- Sasson M, Mallory SB: Malignant primary skin tumors in children. Curr Opin Pediatr 8 (4): 372-7, 1996. [PUBMED Abstract]
- Barnhill RL: Childhood melanoma. Semin Diagn Pathol 15 (3): 189-94, 1998. [PUBMED Abstract]
- Fishman C, Mihm MC Jr, Sober AJ: Diagnosis and management of nevi and cutaneous melanoma in infants and children. Clin Dermatol 20 (1): 44-50, 2002 Jan-Feb. [PUBMED Abstract]
- Hamre MR, Chuba P, Bakhshi S, et al.: Cutaneous melanoma in childhood and adolescence. Pediatr Hematol Oncol 19 (5): 309-17, 2002 Jul-Aug. [PUBMED Abstract]
- Ceballos PI, Ruiz-Maldonado R, Mihm MC Jr: Melanoma in children. N Engl J Med 332 (10): 656-62, 1995. [PUBMED Abstract]
- Schmid-Wendtner MH, Berking C, Baumert J, et al.: Cutaneous melanoma in childhood and adolescence: an analysis of 36 patients. J Am Acad Dermatol 46 (6): 874-9, 2002. [PUBMED Abstract]
- Pappo AS: Melanoma in children and adolescents. Eur J Cancer 39 (18): 2651-61, 2003. [PUBMED Abstract]
- Huynh PM, Grant-Kels JM, Grin CM: Childhood melanoma: update and treatment. Int J Dermatol 44 (9): 715-23, 2005. [PUBMED Abstract]
- Christenson LJ, Borrowman TA, Vachon CM, et al.: Incidence of basal cell and squamous cell carcinomas in a population younger than 40 years. JAMA 294 (6): 681-90, 2005. [PUBMED Abstract]
- Moscarella E, Zalaudek I, Cerroni L, et al.: Excised melanocytic lesions in children and adolescents - a 10-year survey. Br J Dermatol 167 (2): 368-73, 2012. [PUBMED Abstract]
- Bleyer A, O’Leary M, Barr R, et al., eds.: Cancer Epidemiology in Older Adolescents and Young Adults 15 to 29 Years of Age, Including SEER Incidence and Survival: 1975-2000. Bethesda, Md: National Cancer Institute, 2006. NIH Pub. No. 06-5767. Also available online. Last accessed June 07, 2013.
- Horner MJ, Ries LA, Krapcho M, et al.: SEER Cancer Statistics Review, 1975-2006. Bethesda, Md: National Cancer Institute, 2009. Also available online. Last accessed June 07, 2013.
- Shibuya H, Kato A, Kai N, et al.: A case of Werner syndrome with three primary lesions of malignant melanoma. J Dermatol 32 (9): 737-44, 2005. [PUBMED Abstract]
- Kleinerman RA, Yu CL, Little MP, et al.: Variation of second cancer risk by family history of retinoblastoma among long-term survivors. J Clin Oncol 30 (9): 950-7, 2012. [PUBMED Abstract]
- Pappo AS, Kaste SC, Rao BN, et al.: Childhood melanoma. In: Balch CM, Houghton AN, Sober AJ, et al., eds.: Cutaneous Melanoma. 3rd ed., St. Louis, Mo: Quality Medical Publishing Inc., 1998, pp 175-186.
- Heffernan AE, O'Sullivan A: Pediatric sun exposure. Nurse Pract 23 (7): 67-8, 71-8, 83-6, 1998. [PUBMED Abstract]
- Berg P, Lindelöf B: Differences in malignant melanoma between children and adolescents. A 35-year epidemiological study. Arch Dermatol 133 (3): 295-7, 1997. [PUBMED Abstract]
- Elwood JM, Jopson J: Melanoma and sun exposure: an overview of published studies. Int J Cancer 73 (2): 198-203, 1997. [PUBMED Abstract]
- Strouse JJ, Fears TR, Tucker MA, et al.: Pediatric melanoma: risk factor and survival analysis of the surveillance, epidemiology and end results database. J Clin Oncol 23 (21): 4735-41, 2005. [PUBMED Abstract]
- Whiteman DC, Valery P, McWhirter W, et al.: Risk factors for childhood melanoma in Queensland, Australia. Int J Cancer 70 (1): 26-31, 1997. [PUBMED Abstract]
- Tucker MA, Fraser MC, Goldstein AM, et al.: A natural history of melanomas and dysplastic nevi: an atlas of lesions in melanoma-prone families. Cancer 94 (12): 3192-209, 2002. [PUBMED Abstract]
- Ducharme EE, Silverberg NB: Pediatric malignant melanoma: an update on epidemiology, detection, and prevention. Cutis 84 (4): 192-8, 2009. [PUBMED Abstract]
- Hale EK, Stein J, Ben-Porat L, et al.: Association of melanoma and neurocutaneous melanocytosis with large congenital melanocytic naevi--results from the NYU-LCMN registry. Br J Dermatol 152 (3): 512-7, 2005. [PUBMED Abstract]
- Makkar HS, Frieden IJ: Neurocutaneous melanosis. Semin Cutan Med Surg 23 (2): 138-44, 2004. [PUBMED Abstract]
- Paradela S, Fonseca E, Pita-Fernández S, et al.: Prognostic factors for melanoma in children and adolescents: a clinicopathologic, single-center study of 137 Patients. Cancer 116 (18): 4334-44, 2010. [PUBMED Abstract]
- Lange JR, Palis BE, Chang DC, et al.: Melanoma in children and teenagers: an analysis of patients from the National Cancer Data Base. J Clin Oncol 25 (11): 1363-8, 2007. [PUBMED Abstract]
- Rao BN, Hayes FA, Pratt CB, et al.: Malignant melanoma in children: its management and prognosis. J Pediatr Surg 25 (2): 198-203, 1990. [PUBMED Abstract]
- Aldrink JH, Selim MA, Diesen DL, et al.: Pediatric melanoma: a single-institution experience of 150 patients. J Pediatr Surg 44 (8): 1514-21, 2009. [PUBMED Abstract]
- Tcheung WJ, Marcello JE, Puri PK, et al.: Evaluation of 39 cases of pediatric cutaneous head and neck melanoma. J Am Acad Dermatol 65 (2): e37-42, 2011. [PUBMED Abstract]
- Gibbs P, Moore A, Robinson W, et al.: Pediatric melanoma: are recent advances in the management of adult melanoma relevant to the pediatric population. J Pediatr Hematol Oncol 22 (5): 428-32, 2000 Sep-Oct. [PUBMED Abstract]
- Livestro DP, Kaine EM, Michaelson JS, et al.: Melanoma in the young: differences and similarities with adult melanoma: a case-matched controlled analysis. Cancer 110 (3): 614-24, 2007. [PUBMED Abstract]
- Lohmann CM, Coit DG, Brady MS, et al.: Sentinel lymph node biopsy in patients with diagnostically controversial spitzoid melanocytic tumors. Am J Surg Pathol 26 (1): 47-55, 2002. [PUBMED Abstract]
- Su LD, Fullen DR, Sondak VK, et al.: Sentinel lymph node biopsy for patients with problematic spitzoid melanocytic lesions: a report on 18 patients. Cancer 97 (2): 499-507, 2003. [PUBMED Abstract]
- Howman-Giles R, Shaw HM, Scolyer RA, et al.: Sentinel lymph node biopsy in pediatric and adolescent cutaneous melanoma patients. Ann Surg Oncol 17 (1): 138-43, 2010. [PUBMED Abstract]
- Moore-Olufemi S, Herzog C, Warneke C, et al.: Outcomes in pediatric melanoma: comparing prepubertal to adolescent pediatric patients. Ann Surg 253 (6): 1211-5, 2011. [PUBMED Abstract]
- Shah NC, Gerstle JT, Stuart M, et al.: Use of sentinel lymph node biopsy and high-dose interferon in pediatric patients with high-risk melanoma: the Hospital for Sick Children experience. J Pediatr Hematol Oncol 28 (8): 496-500, 2006. [PUBMED Abstract]
- Kayton ML, La Quaglia MP: Sentinel node biopsy for melanocytic tumors in children. Semin Diagn Pathol 25 (2): 95-9, 2008. [PUBMED Abstract]
- Ariyan CE, Coit DG: Clinical aspects of sentinel lymph node biopsy in melanoma. Semin Diagn Pathol 25 (2): 86-94, 2008. [PUBMED Abstract]
- Pacella SJ, Lowe L, Bradford C, et al.: The utility of sentinel lymph node biopsy in head and neck melanoma in the pediatric population. Plast Reconstr Surg 112 (5): 1257-65, 2003. [PUBMED Abstract]
- Navid F, Furman WL, Fleming M, et al.: The feasibility of adjuvant interferon alpha-2b in children with high-risk melanoma. Cancer 103 (4): 780-7, 2005. [PUBMED Abstract]
- Chao MM, Schwartz JL, Wechsler DS, et al.: High-risk surgically resected pediatric melanoma and adjuvant interferon therapy. Pediatr Blood Cancer 44 (5): 441-8, 2005. [PUBMED Abstract]
- Kirkwood JM, Strawderman MH, Ernstoff MS, et al.: Interferon alfa-2b adjuvant therapy of high-risk resected cutaneous melanoma: the Eastern Cooperative Oncology Group Trial EST 1684. J Clin Oncol 14 (1): 7-17, 1996. [PUBMED Abstract]
- Roaten JB, Partrick DA, Bensard D, et al.: Survival in sentinel lymph node-positive pediatric melanoma. J Pediatr Surg 40 (6): 988-92; discussion 992, 2005. [PUBMED Abstract]
- Ludgate MW, Fullen DR, Lee J, et al.: The atypical Spitz tumor of uncertain biologic potential: a series of 67 patients from a single institution. Cancer 115 (3): 631-41, 2009. [PUBMED Abstract]
- Busam KJ, Murali R, Pulitzer M, et al.: Atypical spitzoid melanocytic tumors with positive sentinel lymph nodes in children and teenagers, and comparison with histologically unambiguous and lethal melanomas. Am J Surg Pathol 33 (9): 1386-95, 2009. [PUBMED Abstract]
- Berk DR, LaBuz E, Dadras SS, et al.: Melanoma and melanocytic tumors of uncertain malignant potential in children, adolescents and young adults--the Stanford experience 1995-2008. Pediatr Dermatol 27 (3): 244-54, 2010 May-Jun. [PUBMED Abstract]
- Cerroni L, Barnhill R, Elder D, et al.: Melanocytic tumors of uncertain malignant potential: results of a tutorial held at the XXIX Symposium of the International Society of Dermatopathology in Graz, October 2008. Am J Surg Pathol 34 (3): 314-26, 2010. [PUBMED Abstract]
- Gill M, Renwick N, Silvers DN, et al.: Lack of BRAF mutations in Spitz nevi. J Invest Dermatol 122 (5): 1325-6, 2004. [PUBMED Abstract]
- Bastian BC, Wesselmann U, Pinkel D, et al.: Molecular cytogenetic analysis of Spitz nevi shows clear differences to melanoma. J Invest Dermatol 113 (6): 1065-9, 1999. [PUBMED Abstract]
- Gerami P, Jewell SS, Morrison LE, et al.: Fluorescence in situ hybridization (FISH) as an ancillary diagnostic tool in the diagnosis of melanoma. Am J Surg Pathol 33 (8): 1146-56, 2009. [PUBMED Abstract]
- Massi D, Cesinaro AM, Tomasini C, et al.: Atypical Spitzoid melanocytic tumors: a morphological, mutational, and FISH analysis. J Am Acad Dermatol 64 (5): 919-35, 2011. [PUBMED Abstract]
- van Engen-van Grunsven AC, van Dijk MC, Ruiter DJ, et al.: HRAS-mutated Spitz tumors: A subtype of Spitz tumors with distinct features. Am J Surg Pathol 34 (10): 1436-41, 2010. [PUBMED Abstract]
- Blokx WA, van Dijk MC, Ruiter DJ: Molecular cytogenetics of cutaneous melanocytic lesions - diagnostic, prognostic and therapeutic aspects. Histopathology 56 (1): 121-32, 2010. [PUBMED Abstract]
- Takata M, Saida T: Genetic alterations in melanocytic tumors. J Dermatol Sci 43 (1): 1-10, 2006. [PUBMED Abstract]
- Mu E, Lange JR, Strouse JJ: Comparison of the use and results of sentinel lymph node biopsy in children and young adults with melanoma. Cancer 118 (10): 2700-7, 2012. [PUBMED Abstract]
- Kirkwood JM, Manola J, Ibrahim J, et al.: A pooled analysis of eastern cooperative oncology group and intergroup trials of adjuvant high-dose interferon for melanoma. Clin Cancer Res 10 (5): 1670-7, 2004. [PUBMED Abstract]
- Gogas HJ, Kirkwood JM, Sondak VK: Chemotherapy for metastatic melanoma: time for a change? Cancer 109 (3): 455-64, 2007. [PUBMED Abstract]
- Eton O, Legha SS, Bedikian AY, et al.: Sequential biochemotherapy versus chemotherapy for metastatic melanoma: results from a phase III randomized trial. J Clin Oncol 20 (8): 2045-52, 2002. [PUBMED Abstract]
- Middleton MR, Grob JJ, Aaronson N, et al.: Randomized phase III study of temozolomide versus dacarbazine in the treatment of patients with advanced metastatic malignant melanoma. J Clin Oncol 18 (1): 158-66, 2000. [PUBMED Abstract]
- Chapman PB, Hauschild A, Robert C, et al.: Improved survival with vemurafenib in melanoma with BRAF V600E mutation. N Engl J Med 364 (26): 2507-16, 2011. [PUBMED Abstract]
- Hodi FS, O'Day SJ, McDermott DF, et al.: Improved survival with ipilimumab in patients with metastatic melanoma. N Engl J Med 363 (8): 711-23, 2010. [PUBMED Abstract]
- Efron PA, Chen MK, Glavin FL, et al.: Pediatric basal cell carcinoma: case reports and literature review. J Pediatr Surg 43 (12): 2277-80, 2008. [PUBMED Abstract]
- Griffin JR, Cohen PR, Tschen JA, et al.: Basal cell carcinoma in childhood: case report and literature review. J Am Acad Dermatol 57 (5 Suppl): S97-102, 2007. [PUBMED Abstract]
- Gorlin RJ: Nevoid basal cell carcinoma syndrome. Dermatol Clin 13 (1): 113-25, 1995. [PUBMED Abstract]
- Kimonis VE, Goldstein AM, Pastakia B, et al.: Clinical manifestations in 105 persons with nevoid basal cell carcinoma syndrome. Am J Med Genet 69 (3): 299-308, 1997. [PUBMED Abstract]
- Amlashi SF, Riffaud L, Brassier G, et al.: Nevoid basal cell carcinoma syndrome: relation with desmoplastic medulloblastoma in infancy. A population-based study and review of the literature. Cancer 98 (3): 618-24, 2003. [PUBMED Abstract]
- Veenstra-Knol HE, Scheewe JH, van der Vlist GJ, et al.: Early recognition of basal cell naevus syndrome. Eur J Pediatr 164 (3): 126-30, 2005. [PUBMED Abstract]
- Caro I, Low JA: The role of the hedgehog signaling pathway in the development of basal cell carcinoma and opportunities for treatment. Clin Cancer Res 16 (13): 3335-9, 2010. [PUBMED Abstract]
- Von Hoff DD, LoRusso PM, Rudin CM, et al.: Inhibition of the hedgehog pathway in advanced basal-cell carcinoma. N Engl J Med 361 (12): 1164-72, 2009. [PUBMED Abstract]
- Sekulic A, Migden MR, Oro AE, et al.: Efficacy and safety of vismodegib in advanced basal-cell carcinoma. N Engl J Med 366 (23): 2171-9, 2012. [PUBMED Abstract]
- Tang JY, Mackay-Wiggan JM, Aszterbaum M, et al.: Inhibiting the hedgehog pathway in patients with the basal-cell nevus syndrome. N Engl J Med 366 (23): 2180-8, 2012. [PUBMED Abstract]
- Hoch BL, Nielsen GP, Liebsch NJ, et al.: Base of skull chordomas in children and adolescents: a clinicopathologic study of 73 cases. Am J Surg Pathol 30 (7): 811-8, 2006. [PUBMED Abstract]
- McMaster ML, Goldstein AM, Bromley CM, et al.: Chordoma: incidence and survival patterns in the United States, 1973-1995. Cancer Causes Control 12 (1): 1-11, 2001. [PUBMED Abstract]
- Coffin CM, Swanson PE, Wick MR, et al.: Chordoma in childhood and adolescence. A clinicopathologic analysis of 12 cases. Arch Pathol Lab Med 117 (9): 927-33, 1993. [PUBMED Abstract]
- Borba LA, Al-Mefty O, Mrak RE, et al.: Cranial chordomas in children and adolescents. J Neurosurg 84 (4): 584-91, 1996. [PUBMED Abstract]
- Jian BJ, Bloch OG, Yang I, et al.: A comprehensive analysis of intracranial chordoma and survival: a systematic review. Br J Neurosurg 25 (4): 446-53, 2011. [PUBMED Abstract]
- Yasuda M, Bresson D, Chibbaro S, et al.: Chordomas of the skull base and cervical spine: clinical outcomes associated with a multimodal surgical resection combined with proton-beam radiation in 40 patients. Neurosurg Rev 35 (2): 171-82; discussion 182-3, 2012. [PUBMED Abstract]
- McMaster ML, Goldstein AM, Parry DM: Clinical features distinguish childhood chordoma associated with tuberous sclerosis complex (TSC) from chordoma in the general paediatric population. J Med Genet 48 (7): 444-9, 2011. [PUBMED Abstract]
- Hug EB, Sweeney RA, Nurre PM, et al.: Proton radiotherapy in management of pediatric base of skull tumors. Int J Radiat Oncol Biol Phys 52 (4): 1017-24, 2002. [PUBMED Abstract]
- Noël G, Habrand JL, Jauffret E, et al.: Radiation therapy for chordoma and chondrosarcoma of the skull base and the cervical spine. Prognostic factors and patterns of failure. Strahlenther Onkol 179 (4): 241-8, 2003. [PUBMED Abstract]
- Rutz HP, Weber DC, Goitein G, et al.: Postoperative spot-scanning proton radiation therapy for chordoma and chondrosarcoma in children and adolescents: initial experience at paul scherrer institute. Int J Radiat Oncol Biol Phys 71 (1): 220-5, 2008. [PUBMED Abstract]
- Casali PG, Messina A, Stacchiotti S, et al.: Imatinib mesylate in chordoma. Cancer 101 (9): 2086-97, 2004. [PUBMED Abstract]
- Stacchiotti S, Longhi A, Ferraresi V, et al.: Phase II study of imatinib in advanced chordoma. J Clin Oncol 30 (9): 914-20, 2012. [PUBMED Abstract]
- Lindén O, Stenberg L, Kjellén E: Regression of cervical spinal cord compression in a patient with chordoma following treatment with cetuximab and gefitinib. Acta Oncol 48 (1): 158-9, 2009. [PUBMED Abstract]
- Singhal N, Kotasek D, Parnis FX: Response to erlotinib in a patient with treatment refractory chordoma. Anticancer Drugs 20 (10): 953-5, 2009. [PUBMED Abstract]
- Stacchiotti S, Marrari A, Tamborini E, et al.: Response to imatinib plus sirolimus in advanced chordoma. Ann Oncol 20 (11): 1886-94, 2009. [PUBMED Abstract]
- Kuttesch JF Jr, Parham DM, Kaste SC, et al.: Embryonal malignancies of unknown primary origin in children. Cancer 75 (1): 115-21, 1995. [PUBMED Abstract]
- Pavlidis N, Pentheroudakis G: Cancer of unknown primary site. Lancet 379 (9824): 1428-35, 2012. [PUBMED Abstract]
- Bohuslavizki KH, Klutmann S, Kröger S, et al.: FDG PET detection of unknown primary tumors. J Nucl Med 41 (5): 816-22, 2000. [PUBMED Abstract]
- Han A, Xue J, Hu M, et al.: Clinical value of 18F-FDG PET-CT in detecting primary tumor for patients with carcinoma of unknown primary. Cancer Epidemiol 36 (5): 470-5, 2012. [PUBMED Abstract]
- Varadhachary GR, Talantov D, Raber MN, et al.: Molecular profiling of carcinoma of unknown primary and correlation with clinical evaluation. J Clin Oncol 26 (27): 4442-8, 2008. [PUBMED Abstract]
- Pentheroudakis G, Greco FA, Pavlidis N: Molecular assignment of tissue of origin in cancer of unknown primary may not predict response to therapy or outcome: a systematic literature review. Cancer Treat Rev 35 (3): 221-7, 2009. [PUBMED Abstract]