A CASE OF MULTIPLE ENDOCRINE NEOPLASIA TYPE 2B

A sporadic case of multiple endocrine neoplasia type 2B in a twenty-si x year old man who manifested medullary thyroid carcinoma, multiple mu cosal neuromas of the tongue and a marfanoid habitus is reported. At t he time of diagnosis, he also had multiple liver and lung metastases. Genetic analysis of his lymphocytes revealed a point mutation in exon 16 of the RET proto-oncogene. Since multiple endocrine neoplasia type 2B has a relatively poor prognosis because of the occasional aggressiv e behavior of medullary thyroid carcinoma, the necessity of the geneti c diagnosis of multiple endocrine neoplasia in the early stage is sugg ested.