Abstract Dual ectopic secretion of adrenocorticotropic hormone (ACTH) and growth hormone-releasing hormone (GHRH) by a single neuroendocrine tumor (NET) is extremely rare. We report a 43-year-old woman presenting with acral enlargement, weight gain, hyperpigmentation, and proximal muscle weakness. Laboratory evaluation revealed elevated cortisol, ACTH, and insulin-like growth factor 1 (IGF-1), consistent with concurrent Cushing syndrome and acromegaly. Imaging demonstrated a left hilar mass, and biopsy confirmed a pulmonary NET with immunohistochemical (IHC) positivity for synaptophysin and chromogranin. Pituitary magnetic resonance imaging (MRI) showed diffuse hyperplasia, suggesting trophic stimulation rather than a primary pituitary adenoma. Surgical resection resulted in normalization of hormone levels, marked clinical improvement, and regression of pituitary enlargement. Although direct histologic confirmation of tumor-derived GHRH was unavailable, the reversible pituitary hyperplasia favors ectopic GHRH-mediated stimulation rather than primary ectopic GH secretion. IHC of the resected tumor demonstrated ACTH positivity, supporting ectopic ACTH secretion. This case highlights the importance of recognizing dual hormone–secreting NETs in patients presenting with overlapping endocrine syndromes, as early detection and complete resection can lead to remission.
Sudhakar et al. (Sat,) studied this question.