A 27 year old man presented with complaints of headache and visual disturbance, first noted six months earlier. Simple radiographs of skull sellar widening and calcification. Brain CT revealed a 3 X3 X4 cm-sized sellar suprasellar mass with heavy calcification. T1-weighted MR images showed that the signal intensity of the mass was slightly lower than that of the gray matter, while T2-weighted images showed heterogeneous high signal intensity with central low-signal-intensity foci, suggesting calcification After contrast infusion, enhancement was irregular. Surgery revealed a 4 X5 cm sized, well-demarcated, lobulated mass adhering to the meninges. Papillary-type pituitary adenoma was histologically confirmed. We report the CT and MR findings of atypical pituitary adenoma with extensive internal calcification mimicking craniopharyngioma.