Cystic lymphocytic hypophysitis, visual field defects and hypopituitarism

A 45-year-old man presented with anterior pituitary failure, requiring thyr oxine, hydrocortisone and androgen replacement. An MRI scan revealed a larg e cystic pituitary mass and thickening of the pituitary stalk. Over three y ears, diabetes insipidus and bitemporal hemianopia developed and the cystic mass had enlarged on MR scanning. Transphenoidal resection was performed w ith normalisation of the visual fields. Histology revealed lymphocytic hypo physitis, which is rare in men. The presentation with cystic enlargement is unique.