Endocrine Abstracts

Introduction: We report a patient with a giant prolactinoma due to Multiple Endocrine Neoplasia type 1 (MEN1) with consequential growth hormone deficiency and central hypothyroidism.

Case report: A 12-year-old girl attended the genetic clinic, as her father had MEN-1 mutation. On questioning, she reported severe headaches, increasing in frequency over several months, with fatigue and hair loss. She had breast development for over 2 years, but no menstrual periods. On examination she was on the 98th centile for weight, 50th centile for height. She had no visual impairment. Bloods showed a significantly elevated prolactin of greater than 69 000 with a mono prolactin of greater than 59 000 and MEN-1 mutation was detected. Her MRI showed a large anterior pituitary lesion in keeping with a giant prolactinoma. She was commenced on cabergoline, and prolactin levels improved. Subsequent testing demonstrated pubertal arrest, growth hormone deficiency (peak growth hormone of 2.3 ng/mL) and central hypothyroidism (thyroxine 10.7 pmol/L, TSH–1.34 mIU/L). She was commenced on growth hormone and levothyroxine with a good response. Follow up imaging has shown a reduction in size of the prolactinoma.

Discussion: MEN1 is a rare, autosomal dominant disease which most commonly presents with primary hyperparathyroidism. Only 10% of MEN1 patients present with pituitary tumours, usually prolactinomas, but this is rare in children. MEN1 is diagnosed if an individual has one MEN1 related tumour and a first degree relative with MEN1 mutation or two MEN1-associated tumours. The presentation of pituitary tumours is often varied with non-specific symptoms. They may present with signs of raised intracranial pressure, visual disturbance, symptoms of hypopituitarism (hypoadrenalism, hypogonadism and hypothyroidism) or symptoms of hormone excess (hyperprolactinaemia, Cushing’s disease, gigantism). This case demonstrates a rare presentation of MEN1 with multiple complications. It also highlights the difficulties in diagnosis, as she was assessed due to her family history, despite having multiple symptoms.