RESUMO
BACKGROUND: Multiple endocrine neoplasia syndrome type IIA (MEN IIA) has rarely been encountered in pregnancy. CASE: A 22-year-old, nulliparous woman developed bilateral pheochromocytomas during pregnancy. This finding aroused suspicion for MEN IIA, and close endocrinologic follow-up was arranged. Four years later, hyperparathyroidism developed, and the diagnosis was established. The patient underwent prophylactic total thyroidectomy with parathyroid exploration. CONCLUSION: This was the first case of MEN IIA in pregnancy in which the diagnosis was established prior to the development of medullary thyroid cancer, thereby allowing prophylactic thyroidectomy. The presence of bilateral neoplastic disease in young patients may be indicative of a hereditary predisposition to malignancy.