Multiple endocrine neoplasia, type IIb. Report of a case.

Multiple endocrine neoplasia, type IIb, is a rare syndrome characterized by mucosal neuromas, medullary thyroid carcinoma (MTC), pheochromocytoma and somatic abnormalities. A case of a 10-year-old girl with multiple mucosal neuromas and bilateral MTC is reported. The presumptive diagnosis of MTC was made on the basis of abnormal basal values of calcitonin and increased calcitonin secretion after pentagastrin injection. The manifestations of the syndrome are summarized, and the importance of repeated evaluation of thyroidal C-cell and adrenal medullary function in patients with the characteristic aspect of the syndrome is emphasized.