Pituitary carcinoma

A rare pituitary tumor characterized by the presence of a pituitary adenoma that has metastasized either within the central nervous system, or to distant sites. The vast majority of pituitary carcinomas are hormonally active, most frequently with ACTH or prolactin production. The most common clinical symptoms are diabetes insipidus, optic nerve dysfunction, anterior pituitary dysfunction, palsy of cranial nerves III, IV, or VI, and headaches, although patients may also be asymptomatic. The tumors behave aggressively, and prognosis is poor.