Cytogenetic studies on patients with medullary carcinoma of the thyroid

Cytogenetic studies were carried out on stimulated lymphocyte cultures of patients with medullary carcinoma of the thyroid. Of 32 patients studied, seven had a hereditary carcinoma, and five had multiple endocrine neoplasia type 2A and two had type 2B. Neither a constitutional chromosome abnormality nor an increase in chromosomal breakage were detected in these patients.