Cellular Classification of Malignant Mesothelioma
Histologically, these tumors are composed of fibrous or epithelial elements or both. The epithelial form occasionally causes confusion with peripheral anaplastic lung carcinomas or metastatic carcinomas. Attempts at diagnosis by cytology or needle biopsy of the pleura are often unsuccessful. It can be especially difficult to differentiate mesothelioma from adenocarcinoma on small tissue specimens. Thoracoscopy can be valuable in obtaining adequate tissue specimens for diagnostic purposes. Examination of the gross tumor at surgery and use of special stains or electron microscopy can often help. The special stains reported to be most useful include periodic acid-Schiff diastase, hyaluronic acid, mucicarmine, CEA, and Leu M1. Histologic appearance seems to be of prognostic value, and most clinical studies show that patients with epithelial mesotheliomas have a better prognosis than those with sarcomatous or mixed histology mesotheliomas.[2-4]References
- Boutin C, Rey F: Thoracoscopy in pleural malignant mesothelioma: a prospective study of 188 consecutive patients. Part 1: Diagnosis. Cancer 72 (2): 389-93, 1993. [PUBMED Abstract]
- Chahinian AP, Pass HI: Malignant mesothelioma. In: Holland JC, Frei E, eds.: Cancer Medicine e.5. 5th ed. Hamilton, Ontario: B.C. Decker Inc, 2000, pp 1293-1312.
- Nauta RJ, Osteen RT, Antman KH, et al.: Clinical staging and the tendency of malignant pleural mesotheliomas to remain localized. Ann Thorac Surg 34 (1): 66-70, 1982. [PUBMED Abstract]
- Sugarbaker DJ, Strauss GM, Lynch TJ, et al.: Node status has prognostic significance in the multimodality therapy of diffuse, malignant mesothelioma. J Clin Oncol 11 (6): 1172-8, 1993. [PUBMED Abstract]