Malignant prolactinoma: a rare case report.

Pituitary carcinomas are rare adenohypophyseal tumors with cerebrospinal or extracranial metastasis. None of the histologic findings distinguish pituitary adenoma from carcinoma. We describe clinico-pathological and immunohistological features of malignant prolactinoma. The patient initially presented with a prolactin-secreting pituitary adenoma. The tumor showed aggressive clinical course presenting with repeated recurrences and eventually metastasized to multiple bones. MIB-1 and p53 labeling indices were also compared in primary adenoma, recurrent invasive adenoma and metastatic tumor.