SUN-274 Pituitary Macroadenoma Treated with Peptide Receptor Radionuclide Therapy in a Patient with Common Variable Immunodeficiency - Case Report

Background: Nonfunctional adenomas comprise 25-35% of all pituitary tumors, 70-90% of these are gonadatroph cell adenomas. While ‘silent’ adenoma is the most common type of pituitary macroadenoma. The incidence of silent adenomas is estimated at 22/100000. Common Variable Immune Deficiency (CVID) is the most common primary immune disorder which is associated with neoplasia, mostly of the lymphatic or digestive system. We present probably the first case report of gonadotropinoma in a patient with CVID, treated with PRRT. Clinical Case: A 45-year-old man has been a patient at the Endocrinology Clinic for 12 years. Aged 33 years, he was diagnosed with a common variable immunodeficiency. The human immunoglobulin treatment was included. He also suffered from severe, spreading headaches. MRI of the head was performed. A 45mm tumor was found in the sella turcica, spreading to the sphenoid sinus. The tumor was slipped into the epidural reservois and both cavernous sinuses, causing compression of the internal carotid arteries and compressed the optic chiasm. Laboratory tests were as follows: TSH 2.18uIU/ml, LH 4.26mIU/ml, FSH 9.76 mIU/ml, ACTH 25.88pg/ml, PRL 18.34 ng/ml, HGH 3.9uU/ml, normal plasma and urine osmolality. So, the silent pituitary macroadenoma was diagnosed. Endoscopic transsphenoidal incomplete tumor resection was performed. The operation was complicated by massive parenchymal bleeding. Histopatological examination confirmed presence of pituitary adenoma, and immunohistochemical positive staining also of FSH (+), subunit alpha (+), TSH (+/-). A Ki67 proliferation index was 1%. After 12 months endoscopic reoperation was performed. The extent of operation was larger but not total. After 12 month the tumor mass increased (50x50x45mm). Imaging of somatostatin receptors by SPECT-CT was performed. It showed a heterogeneous radiolabel accumulation in the pituitary tumor. In 2010, 2 doses of 200mCi 90-Y-DOTATATE were administered with good effect. Tumor size was reduced to 20x23x25mm. The patient has had no headache for that time. Since 2011 he has also been treated with octreotide30 mg/month, with good therapy tolerance. Conclusion: This is probably the first description of a 12-year history of complicated but successful treatment of pituitary silent macroadenoma. It was also probably the first use of PRRT in the pituitary tumor with excellent effect. The patient remains in a very good condition, without neurological symptoms and no disorders of pituitary function.