[Pathology of pituitary incidentaloma]

With advance of neuroimaging technics, incidentally discovered pituitary masses (pituitary incidentalomas) are recently increased. In autopsy cases, pituitary adenomas have been discovered at the rate of 1.5-27% (mean 10%). More than 80% of these adenomas were smaller than 3 mm. Adenomas larger than 10 mm were extremely rare. Histologically autopsy adenomas were mostly PRL cell adenomas (PRLomas) and gonadotroph adenomas. Histology of autopsy PRLomas was different from that of surgically resected PRLomas. Clinically discovered pituitary incidentalomas include pituitary adenomas, Rathke's cleft cysts, and craniopharyngiomas. Most of incidental adenomas were histologically gonadotroph adenomas in our materials. Perphaps, autopsy adenomas may not grow to the clinically found incidentalomas.