Abstract

Ectopic growth hormone releasing hormone (GHRH) secretion is a rare cause of acromegaly and accounts for <1% of cases. It is most commonly secondary to gastropancreatic neuroendocrine tumours and bronchial carcinoid tumours. We report a case of 57 years old man with adrenal phaeochromocytoma and acromegaly due to ectopic GHRH secretion in a patient with neurofibromatosis type 1. He presented with headache, sweating and newly diagnosed diabetes. The diagnosis was of acromegaly and pheochromocytoma was confirmed on investigations and imaging. Surgical removal of the pheochromocytoma in this case resulted in resolution of his diabetes, normalisation of his IGF-1 with adequate GH suppression on oral glucose tolerance test (OGTT) and regression of enlarged pituitary on postoperative magnetic resonance imaging (MRI) scan. To our knowledge, this is the first case of acromegaly associated with pheochromocytoma due to ectopic GHRH in a patient of neurofibromatosis in literature.

Key words: Growth hormone releasing hormone (GHRH), pheochromocytoma, acromegaly, somatotrophs, neurofibromatosis.

Abbreviation

GHRH, Growth hormone releasing hormone; OGTT, oral glucose tolerance test.