A 21-year-old man presented with bitemporal hemianopia and hyperprolactinemia. Magnetic resonance (MR) imaging showed a suprasellar cystic tumor in contact with the pituitary stalk. The diagnosis was craniopharyngioma. Intraoperatively, there was no clear continuity between the tumor and the tissue of the anterior lobe of the pituitary gland. The pituitary stalk and the diaphragma sellae were intact, and their morphology remained almost completely normal after the tumor was removed. The histological diagnosis was prolactin-producing pituitary adenoma. Postoperatively, the bitemporal hemianopia improved, and the serum prolactin levels returned to normal. The final diagnosis was suprasellar ectopic pituitary adenoma arising in the peri-infundibular region. Follow-up MR imaging at 1 year showed a normal pituitary stalk and pituitary gland, with no evidence of residual tumor.
