SAT-LB310 A Mysterious Multiple Endocrine Neoplasia (MEN) Like Syndrome

Multiple endocrine neoplasia (MEN) is characterized by the occurrence of tumors involving two or more endocrine glands in a single patient. Among the four MEN syndromes, MEN4 due to CDKN1B mutation is characterized by parathyroid and anterior pituitary tumors in possible association with tumors of the adrenals, kidneys, and reproductive organs. We presented a patient with MEN 4 like syndrome without CDKN1B, menin or RET mutations. 74 year old male was diagnosed with acromegaly and primary hyperparathyroidism at age 63. Genetic testing revealed no mutations in menin and RET genes. At age 68, he was diagnosed with renal cell carcinoma (RCC) and at age 70, 2cm left adrenal mass was identified on surveillance computerized tomography (CT). No biochemical workup was pursued. Four years later, he developed hypertensive crisis during spine surgery at our institution. Workup revealed elevated plasma metanephrine (490 pg/ml, normal <57) and normetanephrine (1333 pg/ml, normal <148). CT showed the left adrenal mass increased in size to 4.5 cm. Family history is negative for any endocrine tumors. He underwent repeat genetic testing. Analyses of 133 gene panel reported no germline mutations in menin, RET, CDKN1B, NF12, VHL, SDH and other genes tested but there were variants of uncertain significance (VUS) identified in CHEK2 c.14C>T (p.Ser5Leu) and PTCH2 c.2812G>A (p.Gly938Ser). Patient successfully underwent left adrenalectomy after alpha blockage. Paired tumor-normal sequencing of the resected tumor detected a pathogenic deletion frameshift mutation in NF1 with loss of heterozygosity (LOH) along with copy number alterations with losses in 1p34.1-p11.2, 11p11.2-15.4, 11q14.1-q25 and 17q11.2 (including NF1). VUSs were also detected including CDKN1A C117Y variant, and CHD2P80L. Since germline and tumor testing failed to reveal any known pathogenic variants, whole exome sequencing (pending) will be pursued. The presentation with RCC, pheochromocytoma, pituitary adenoma and parathyroid adenoma is consistent with a MEN syndrome in this patient despite no known pathogenic MEN mutations detected. Somatic mutation in NF1 is a common finding in pheochromocytoma. The biochemical phenotype of pheochromocytoma (elevated metanephrines) is consistent with cluster 2 tumors of kinase signaling pathway as seen in tumors of MEN syndrome and neurofibromatosis. We hope to gain more insight via whole exome sequencing to evaluate for potential novel gene mutation(s).