Endocrine Abstracts

Introduction: The association of papillary carcinoma with medullary thyroid carcinoma may in rare cases be found in some members of families with multiple endocrine neoplasia type 2a (MEN 2a).

Case Report: A 38-year-old patient with a family history of papillary thyroid carcinoma (PTC), operated for multinodular goiter classified Tirads 4 by total thyroidectomy, the anatomopathological examination concluded to a lobar medullary thyroid carcinoma (MTC) of 20mm and an isthmic PTC of 5mm. Calcitonin was not measured preoperatively and was negative postoperatively. The patient was put on LT4 suppression treatement. The genetic study showed a mutation in exon 10 of the RET gene in favor of MEN 2a. The search for other components of MEN 2a revealed a pheochromocytoma of the left adrenal gland, the patient was referred for surgery and a family genetic study was requested.

Discussion: PTC may be associated with sporadic CMT or CMT in patients with MEN 2a with RET proto-oncogene mutation. In MEN 2a, some germline RET mutations have oncogenic activity on thyroid follicular cells. Nevertheless, this activity remains modest and occurs in specific circumstances explaining the rare occurrence of PTC in this context. This observation underlines the importance of calcitonin determination before surgery in case of thyroid nodules to avoid inappropriate therapeutic management

Bibliography: M. Hani. L’association du carcinome papillaire au carcinome médullaire thyroïdien dans la néoplasie endocrinienne multiple type 2a. SFE Bordeaux 2016/Annales d’Endocrinologie 77 (2016) 486-497