A case of prolactin-secreting pituitary carcinoma and its histological findings

Pituitary carcinomas are very rare. The diagnosis of pituitary carcinoma is defined by evidence of craniospinal and/or systemic metastasis, rather than by histological malignancies. We report a case of prolactin-secreting pituitary macroadenoma invading the cavernous sinuses at the time of initial treatment, which later metastasized to the cerebellum, medulla oblongata, and spinal axis. The patient survived approximately nine years following the initial diagnosis of a pituitary tumor and two years following the diagnosis of metastatic disease. Histological examination of the metastatic cerebellar tumor showed an adenoma with high cellularity and hyperchromasia, but no mitoses.