Cellular Classification of Hypopharyngeal Cancer

Almost all hypopharyngeal cancers are epithelial in origin, predominantly squamous cell (i.e., epidermoid) carcinomas (SCCs), and may be preceded by various precancerous lesions.[1,2] Rare types of hypopharyngeal carcinomas include the following:

• Basaloid squamoid carcinomas.
• Spindle-cell (i.e., sarcomatoid) carcinomas.
• Small-cell carcinomas.
• Nasopharyngeal-type undifferentiated carcinomas (i.e., lymphoepitheliomas).
• Carcinomas of the minor salivary glands.

Nonepithelial tumors, including lymphomas, sarcomas, and melanomas, require separate consideration and are not included in the staging and treatment options discussed in this summary.[1,3-8]

Invasive SCCs are usually moderately differentiated or poorly differentiated and invariably stain positively for keratin.[1] In situ carcinoma is often seen adjacent to invasive SCC.[1,9]

The term, leukoplakia, should be used only as a clinically descriptive term meaning that the observer sees a white patch that does not rub off, the significance of which depends on the histologic findings.[10] Based on this description, leukoplakia can range from hyperkeratosis to an actual early invasive carcinoma or may represent only a fungal infection, lichen planus, or other benign oral disease.

1. Oral cavity and oropharynx. In: Rosai J, ed.: Ackerman's Surgical Pathology. 8th ed. St. Louis, Mo: Mosby, 1996, pp 223-55. 
   
   
2. Mendenhall WM, Werning JW, Pfister DG: Treatment of head and neck cancer. In: DeVita VT Jr, Lawrence TS, Rosenberg SA: Cancer: Principles and Practice of Oncology. 9th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2011, pp 729-80. 
   
   
3. Ibrahim NB, Briggs JC, Corbishley CM: Extrapulmonary oat cell carcinoma. Cancer 54 (8): 1645-61, 1984.  [PUBMED Abstract]
   
   
4. Stanley RJ, Weiland LH, DeSanto LW, et al.: Lymphoepithelioma (undifferentiated carcinoma) of the laryngohypopharynx. Laryngoscope 95 (9 Pt 1): 1077-81, 1985.  [PUBMED Abstract]
   
   
5. McKay MJ, Bilous AM: Basaloid-squamous carcinoma of the hypopharynx. Cancer 63 (12): 2528-31, 1989.  [PUBMED Abstract]
   
   
6. Frank DK, Cheron F, Cho H, et al.: Nonnasopharyngeal lymphoepitheliomas (undifferentiated carcinomas) of the upper aerodigestive tract. Ann Otol Rhinol Laryngol 104 (4 Pt 1): 305-10, 1995.  [PUBMED Abstract]
   
   
7. Olsen KD, Lewis JE, Suman VJ: Spindle cell carcinoma of the larynx and hypopharynx. Otolaryngol Head Neck Surg 116 (1): 47-52, 1997.  [PUBMED Abstract]
   
   
8. Lengyel E, Gilde K, Remenár E, et al.: Malignant mucosal melanoma of the head and neck. Pathol Oncol Res 9 (1): 7-12, 2003.  [PUBMED Abstract]
   
   
9. Helliwell TR: acp Best Practice No 169. Evidence based pathology: squamous carcinoma of the hypopharynx. J Clin Pathol 56 (2): 81-5, 2003.  [PUBMED Abstract]
   
   
10. Neville BW, Day TA: Oral cancer and precancerous lesions. CA Cancer J Clin 52 (4): 195-215, 2002 Jul-Aug.  [PUBMED Abstract]