Do Macroprolactinomas need multiple endocrine neoplasia 1 screening: Lesson learnt

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant condition with predisposition to tumors of the parathyroid glands (which occur in the large majority of patients by age 50 years), anterior pituitary, and enteropancreatic endocrine cells. Pituitary tumors as the first presentation of MEN 1 account for 15% of which prolactinoma is the most common, whereas 3% of patients with anterior pituitary tumors will have MEN1. We report an unusual presentation of MEN1, where a middle-aged male presented at 43 years of age with primary hyperparathyroidism after initially having been diagnosed as having giant prolactinoma during the second decade of life. In the recent guidelines for MEN1 management, the genetic analysis of MEN1 is not specifically recommended in this kind of population (age ≤30 years). In patients diagnosed with sporadic macroadenoma before 30 years of age, we suggest to perform MEN1 genetic screening as there is a strong impact of MEN1 mutations in terms of genetic counseling and therapeutic management. In all young patients with pituitary adenomas, hyperparathyroidism should be actively searched. This case highlights the need of considering MEN1 mutations in the young sporadic pituitary macroprolactinoma population.