Pituicytoma Presenting With Hypogonadotropic Hypogonadism in a Highly Vascular Sellar and Suprasellar Mass: A Case Report

Pituicytoma is a rare low-grade tumor arising from the pituicyte lineage of the posterior pituitary and infundibular region.Because its clinical and magnetic resonance imaging (MRI) features overlap with those of more common sellar tumors and because it is often highly vascular, preoperative diagnosis and surgical management can be challenging.We presented a 45-year-old man who presented with four years of fatigue, reduced libido, erectile dysfunction, and intermittent frontal headache.Early-morning biochemical testing showed low total testosterone (8.9 nmol/L), with inappropriately normal luteinizing hormone (LH) and follicle-stimulating hormone (FSH), consistent with secondary hypogonadism.Pituitary magnetic resonance imaging showed a 25 × 28 × 27 mm sellar and suprasellar mass with cavernous sinus extension and superior displacement of the optic chiasm; radiologically, the lesion was initially interpreted as a pituitary macroadenoma.Because of concern regarding vascularity, computed tomography (CT) cerebral angiography was performed and demonstrated a hypertrophied right meningo-hypophyseal trunk supplying the tumor.Due to the anticipated risk of major intraoperative hemorrhage, partial surgical debulking was performed.Histopathology and immunohistochemistry supported the diagnosis of pituicytoma.Testosterone replacement increased serum testosterone.Six weeks after surgery, the patient developed secondary adrenal insufficiency and was commenced on hydrocortisone replacement.Radiotherapy was planned for the substantial residual tumor.This case highlights the importance of considering pituicytoma in the differential diagnosis of an enhancing sellar or suprasellar mass with pituitary dysfunction, particularly when marked vascularity is suspected.Preoperative vascular assessment and multidisciplinary management are important when complete resection may carry substantial hemorrhagic risk.