[Diagnosis of familial medullary cancers].

Medullary thyroid carcinoma (MTC) is hereditary in 20 to 25% of cases. It is inherited as an autosomal dominant trait. MTC can be considered as a sporadic form only after a clinical and biological survey of the two parents, siblings and children of the patient, using pentagastrin stimulation test. The authors have studied 36 patients from 26 families. Hereditary MTC with different clinical features, were discovered in two kindreds. The systematic investigation leads to the discovery of 7 cases in the first family, and of 3 in the second. The treatment of the disease at the first stage of its evolution has been possible when an early diagnosis had been made, such as in the second family.