LBMON138 Leg Tumeo: Is It Neuroendocrine Tumor?

INTRODUCTION: Neuroendocrine tumors (NETs) are heterogenous group of epithelial neoplasms often known to produce and secrete peptides and bioamines. The presentation varies from symptomatic functional to non-functional tumors. The functional tumors cause symptoms based on the substance secreted: corticotropin, gastrin, glucagon, insulin, norepinephrine, serotonin, somatostatin, etc. The prognosis ranges from well-differentiated tumors being indolent while the poorly differentiated forms are aggressive. We present a case with an atypical presentation of NET which was noted to secrete an atypical hormone, cortisol. CASE PRESENTATION: A 55-year-old Caucasian man presented with bilateral lower extremity grade 3 pitting edema for past 2 weeks. His past medical history was significant for hypertension. Lower extremity doppler showed no evidence of deep vein thrombosis. Serum potassium was critically low at 1.9mmol/L. Computed tomography of abdomen and pelvis showed a large mass involving the right hepatic lobe, upper pole of right kidney and hypoattenuated lesions in left hepatic lobe. The intrahepatic inferior vena cava appeared to be severely compressed by the mass. MRI abdomen was suggestive of hepatocellular cancer but alfaprotein levels was normal. Biochemical testing for evaluation of hormonal hypersecretion showed elevated cortisol levels (57.2mcg/dl) and markedly elevated dehydroepiandrosterone sulfate (2641mcg/dl). Serum adrenocorticotrophic hormone and aldosterone levels were within normal limits. Low dose dexamethasone suppression test showed no decline in serum cortisol level reflecting adrenal origin. Urinary evaluation showed elevated cortisol but normal metanephrine and catecholamine levels. With concerns for adrenal carcinoma, right adrenal mass biopsy was performed. The biopsy showed poorly differentiated malignant neoplasm with neuroendocrine features. Tumor cells were positive for synaptophysin (a marker for neuroendocrine differentiation) and CD 138. Soon after, he progressed to multisystem organ failure, tumor lysis syndrome and resorted to comfort care. The patient passed away within a week of diagnosis. CONCLUSION: NETs usually originate in gastrointestinal tract, pancreas, adrenal, lung and rarely genitourinary tract. The incidence of NETs is on the rise with increased detection by imaging. Adrenal NETs, well-known as pheochromocytoma are mostly benign but small cell adrenal neuroendocrine carcinomas are rare and have a grave prognosis. Flushing, diarrhea are the commonest presentations (75-85%) for gastrointestinal NETs and symptoms are based on the substance secreted. This case highlights a case of adrenal neuroendocrine cancer presenting with lower extremity swelling and secreting an uncommon hormone, cortisol. Increasing awareness among the medical fraternity will help with early diagnosis and better outcomes. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.