[Medullary thyroid carcinoma in a 10-month-old child with multiple endocrine neoplasia 2B].

In infants at risk of multiple endocrine neoplasia type 2B (MEN2B) the American Thyroid Association recommends genetic testing as soon as possible after birth and that thyroidectomy should be performed in MEN2B RET-mutation positive individuals as soon as possible and if possible within the first year of life. We present a ten-month-old girl with MEN2B who had prophylactic thyroidectomy. The surgical specimen showed medullary thyroid carcinoma. This case emphasizes the need for early diagnosis and prophylactic thyroidectomy in MEN2B patients.