Endocrine Abstracts

Pituitary adenomas are the most common cause of pituitary lesions. Atypical teratoid rhabdoid tumors are rare aggressive tumors of the central nervous system and are generally seen in children younger than 2 years of age, but also rarely in adults. Only 18 cases have been reported with pituitary involvement to 2018. Median survival in these tumors in adults is 21 months and the cause of death is usually tumor recurrence or leptomeningeal spread. Although surgery, chemotherapy and radiotherapy are used in treatment, a standardized treatment scheme has not been established for adults yet. A fifty-five-year-old woman presented to the hospital for a headache that started about 1 month ago. The patient also had a complaint of visual impairment that started 10 days ago. There was no additional problem in the patient’s history, except for the diagnosis of diabetes mellitus, which started 1.5 years ago and regulated with metformin. On physical examination, visual acuity was decreased in both eyes with limited vision and looking down. In pituitary MRI, partial bleeding macroadenoma with 4 × 3 × 3 cm diameter filling the sellae, infiltrating the stalk and left cavernous sinus, filling the tuberculum sella, prepontine cystern and suprasellar cysternia were seen. The patient was found to have total pituitary insufficiency. She was given the operation with hydrocortisone and L-thyroxine treatment. Pathology: Macroscopically, approximately 3 cc volume tissue were examined. In microscopic sections, cellular undifferentiated tumor cells with narrow cytoplasm, vesicular nuclei, prominent nucleoli showing solid growth were seen. Necrosis and frequent mitosis were observed. Normal pituitary tissue was not seen. In immunohistochemical examination, GFAP, NSE, lymphoid (CD3, CD20, CD30), germ cell (PLAP), hormonal (LH, FSH, GH, TSH, ACTH) markers were negative. Epithelial markers (EMA, LMWK, pankeratin) were observed with focal staining and INI1 was lost. Ki67 proliferation index was found high (50%) in accordance with the mitotic index. These findings were reported as atypical teratoid rhabdoid tumor. In the PET/CT examination performed on the 15th day after the operation, a massive lesion with an intense pathological increase of SUV max. The patient was started on postoperative radiotherapy and the treatment of the vincrist, but despite this treatment, her vision disappeared in the following period, her consciousness gradually decreased. The patient died later. Atypical teratoid rhabdoid tumors of pituitary are rarely seen. they are resistant to treatment and can cause mortality by showing rapid progression.