[Current aspects of the pathology, diagnosis and therapy of C-cell carcinoma. A symposium held in Bonn, July 1991].

An essential element in the histological differentiation of medullary thyroid cancer (MTC) from other thyroid tumors is the use of immunohistochemical methods. The detection of calcitonin in the tumor cells is decisive. Factors which impair the prognosis of MTC are age (> 40 y), male sex, elevated DNA-content and mitotic activity of the tumor cells, immunoreactivity against dopa decarboxylase, histaminase and Leu-M1-antigen. Family screening is based mainly on calcitonin-stimulation tests (using pentagastrin or calcium) as a genetic marker for routine screening is not available yet. Scintigraphic methods using 99mTc-(V)-DMSA, 201Tl-chloride or 99mTc-anti-CEA antibodies become more important, especially in the detection of recurrent disease. Selective venous blood sampling is another sensitive method for localizing recurrent disease. Surgical treatment plays the dominant role in the management of MTC. Complete thyroidectomy in conjunction with systematic lymphadenectomy is now the primary treatment of choice.