In addition to a brief characteristic of the syndrome of multiple endocrine neoplasia type 2 and medullary thyroid carcinoma with a familial incidence which is a prerequisite of the syndrome, the authors submit an account on a group of 53 patients who were on the authors' records during the past 12 years. During this period the disease is systematically searched for in the families of newly diagnosed patients by examining the immunoreactive calcitonin level of relatives. Familial variants account for 28% of all medullary thyroid carcinomas. Patients who are on the records so far belong to 24 families. Approximately twice as often an isolated variant of the familial type of medullary carcinoma is involved, as compared with association with another endocrine affection, in particular pheochromocytoma (Sipple's syndrome), but associated forms will increase in number perspectively (multiple endocrine neoplasia 2A). The syndrome of multiple endocrine neoplasia 2B is very malignant but in view of the typical phenotype the disease should be diagnosed already before the change to malignancy--once the disease develops into the clinical stage the course is very adverse. From the original number of all familial tumours 38 subjects survive (72%), incl 22 who were subjected to bilateral total thyroidectomy based on screening in the preclinical stage. The prognosis of these individuals is very favourable, the calcitonin levels are throughout the follow-up period (2-10 years) repeatedly negative. With regard to the possible association with another endocrinopathy (pheochromocytoma or hyperparathyroidism) all must be followed up systematically (screening) with regard to the manifestation of an associated endocrinopathy frequently only after a longer time interval.

Keywords: Adult; Carcinoma /genetics/; Child; Female; Humans; Male; Multiple Endocrine Neoplasia /genetics/; Pedigree; Thyroid Neoplasms /genetics/