Plurihormonal pituitary adenoma cosecreting ACTH and GH: a rare cause of Cushing's disease.

Plurihormonal pituitary adenomas are rare forms of pituitary adenomas that express more than one hormone. The most common association is with growth hormone (GH) and prolactin. Cosecretion of GH and adrenocorticotrophic hormone (ACTH) is rare with only 25 reported cases in literature. Most presented with features of GH excess, and only four presented with Cushing's disease. We report a case of a woman in her 30s with recurrent plurihormonal pituitary macroadenoma cosecreting GH and ACTH, diagnosed during workup for polycystic ovarian syndrome, and both times presenting uniquely with Cushing's disease. Biochemical testing showed GH excess and hypercortisolism. She underwent transsphenoidal surgery twice and immunohistochemistry showed positive staining for GH and ACTH on both occasions. We aim to raise more awareness of this rare type of pituitary adenoma, shed light on the importance of recognising rare presentations and highlight the necessity of rigorous follow-up given morbidity and potentially higher mortality risk.