PSUN370 Refractory Hypoglycemia Associated with a Metastatic Neuroendocrine Tumor Producing Multiple Hormones

Abstract

Abstract Introduction Neuroendocrine tumors are rare. They are derived from hormone-producing and nerve cells mostly found in GI tract, lung or pancreas. In about half of the cases, work-up does not detect any tumor-related hormone secretion. Even less common, the tumor produces several hormones which may be associated with clinical symptoms. Clinical Case A frail 81-year-old male with mild-to-moderate dementia and no history of diabetes presented to the emergency department with complaints of generalized weakness, fatigue, weight loss, poor appetite, diarrhea and shortness of breath for 1-2 weeks. Physical examination was pertinent for cachexia, general pallor, dry oral mucosa and having heme positive stool. Initial laboratory work-up found anemia (Hg 5.8g/dl), low glucose of 43 mg/dL, hypoalbuminemia (Alb 1.9 gm/dL). CT angiogram of abdomen did not show any active bleed but showed incidental diffuse hepatic lesions favoring metastatic disease, pancreatic ductal dilatation and fluid-filled loops of small and large bowel compatible with enteritis. Subsequent endoscopy and colonoscopy were negative for malignancy. Findings of multiple liver lesions prompted a CT-guided liver biopsy which showed a metastatic, well differentiated neuroendocrine tumor WHO grade II/III with positive stains for chromogranin A, synaptophysin, cytokeratin Oscar (Ki-67 less than 20%). MRCP abdomen examination of pancreas showed no focal pancreatic lesions but was suboptimal due to motion artefacts and lack of contrast. Workup for the tumor revealed increased serum serotonin (772 ng/ml), increased 5-HIAA (3,175 ng/ml), increased chromogranin A (48,436 ng/ml) and an increased 24hr Urine 5-HIAA (162mg/24hr). Further workup for the persistent and hypoglycemia showed a random cortisol 24.6mcg/dl. During hypoglycemia, insulin and C-peptide levels were 4.3 uU/L and 1.4ng/ml indicating inappropriately "normal" insulin production consistent with an insulinoma. IGF 1 and IGF 2 levels were withing the normal range. The hypoglycemia was initially managed with continuous intravenous administration of dextrose and optimization of oral intake, glucagon and octreotide 50 mcg every 8 hours. However, the response to octreotide was insufficient and we were unable to wean the patient off the dextrose. Subsequently we started prednisone 20 mg oral daily and glucose tablets which allowed us to discontinue the intravenous dextrose and the octreotide. Patient was discharged home on hospice care. Conclusion Hypoglycemia is a potentially life-threatening condition necessitating prompt action including the administration of intravenous dextrose. The results of the workup indicate that the neuroendocrine tumor produced excessive amounts of both serotonin and insulin contributing to prolonged refractory hypoglycemia. Treatment of this rare condition is challenging and often empirical. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.