Pituitary malignancies are rare. The definition of pituitary malignancy is still subject to debate. Three types of malignancy with the description of clinical course and complete autopsy were presented; i) true carcinosarcoma, ii) ectopic sphenoid invasive tumor, and iii) post-irradiation sarcoma. The first true carcinosarcoma had a long natural tumor history of 46 years, ending in malignant transformation with extracranial metastasis from a pituitary adenoma. The second ectopic sphenoid tumor was prolactin-producing, locally invasive, with the intact pituitary gland. The third post-irradiation sarcoma was followed by chromophobe pituitary adenoma. The interval between irradiation to the adenoma and malignant transformation to fibrosarcoma was about 14 years.