A Case of Acromegaly Diagnosed After Pituitary Apoplexy Presenting as Polycystic Ovary Syndrome

Dydrogesterone-induced Pituitary Apoplexy

Abstract

Pituitary apoplexy (PA) is an uncommon neuroendocrine emergency resulting from hemorrhage or infarction of a pituitary adenoma. Dopaminergic agents are well-established precipitants; however, the role of synthetic progestins remains insufficiently characterized. Acromegaly may present with clinical features that overlap considerably with those of polycystic ovary syndrome (PCOS), thereby complicating and delaying its diagnosis. We report a 26-year-old woman with a two-year history of secondary amenorrhea and hirsutism who had previously been evaluated by gynecology and diagnosed with PCOS on the basis of oligomenorrhea, clinical hyperandrogenism, and polycystic ovarian morphology on ultrasonography. Markedly elevated prolactin (127 µg/L) and a low free T4 level were also documented; however, the possibility of an underlying pituitary pathology was not investigated at that time. Dydrogesterone was commenced, and twelve days later the patient developed thunderclap headache and acute complete visual loss. Emergency evaluation demonstrated markedly elevated insulin-like growth factor-1 (984 ng/mL) and growth hormone (20 µg/L). Pituitary magnetic resonance imaging revealed a 50×25 mm macroadenoma with signal characteristics consistent with acute hemorrhage and infarction. Emergency transsphenoidal surgery was performed, and histopathology confirmed a sparsely granulated somatotroph pituitary neuroendocrine tumor of the Pit-1 lineage (Ki-67: 8%). The postoperative course was complicated by panhypopituitarism and permanent bilateral visual loss. This case underscores the importance of excluding sellar pathology before initiating hormonal therapy in patients with menstrual irregularities and subtle endocrine disturbances, particularly when features suggestive of acromegaly are present. It also highlights the need for broader awareness of acromegaly’s clinical manifestations among non-endocrinology specialists.