Pituitary infundibular epidermoid cyst: a rare cause of hypopituitarism.

A 53-year-old man presented with 6 months history of weight loss associated with nausea, fatigue, dizziness and headache. On arrival he was in adrenal crisis. Biochemistry revealed anterior hypopituitarism with low cortisol, thyroxine, testosterone and a slightly raised prolactin. He was commenced on steroids, thyroxine and testosterone. MRI pituitary gland was reported to have a 9.4 mm microadenoma. Cabergoline was started for a possible microprolactinoma. Follow-up MRI showed increase in the size of complex cystic lesion causing chiasmal compression raising a possibility of craniopharyngioma. Visual fields assessment was normal. In view of the rapid enlargement, to protect vision and obtain a tissue diagnosis he underwent endoscopic trans-sphenoidal surgery. A cystic lesion was noted intraoperatively originating from pituitary stalk with intrasellar and suprasellar extension. It was filled with white caseous material and fluid. Histology revealed epidermoid cyst. His headache resolved postoperatively.