ACTH secreting pituitary carcinoma: Rare, durable response to concurrent chemotherapy and re-irradiation with a review of the literature. Recurrent pituitary carcinoma re-irradiation

Abstract Pituitary carcinoma (PC) is an uncommon intracranial malignancy with a high rate of metastasis, mortality, and inconsistent response to therapy. Because PC is a rare condition (0.1%-0.2% of pituitary tumors), prospective studies and observable data are scarce. Some PC may have an endocrine secretory function and can arise from existing pituitary adenomas. Treatment often includes a combination of surgical resection, radiotherapy, and systemic therapies. Because of the poor treatment response rate and rapid progression, treatment is often palliative. Here we describe a unique, complete amelioration of severe Cushing's disease due to an ACTH secreting pituitary carcinoma followed by the development of pituitary hypoadrenalism after re-irradiation with concurrent temozolomide.