Abstract #1412022: A Rare Case of Multiple Endocrine Neoplasia Type 1 (MEN1) Presenting with Recurrent Abdominal Pain

Abstract

MEN1 is a rare genetic disorder characterized by combined occurrence of two or more tumors involving parathyroid, anterior pituitary and the neuroendocrine tissue of gastro-entero-pancreatic organ system. We present a case of a young male with recurrent abdominal pain who was later diagnosed with MEN1 syndrome. 27-year-old male with past medical history of chronic abdominal pain presented for an episode of acute upper abdominal pain which was constant and worsened with any movement or palpation. His family history was significant for father having parathyroid disorder and skin lesions. On examination, he was ill appearing with tachycardia, multiple skin lesions and tenderness in upper abdomen. Labs were significant for leukocytosis and hypercalcemia (corrected level 10.5 mg/dl). Rest of the electrolytes, kidney function, liver enzymes and lipase were normal. Computed tomography (CT) abdomen showed inflammatory changes and thickening along the distal stomach/proximal duodenum with scattered free air, concerning for a perforated ulcer. Indeterminate bilateral adrenal nodules were also noted. Patient underwent emergent exploratory laparotomy and was noted to have small perforation in the anterior proximal portion of the duodenum which was repaired. Post-operatively, work up for persistent hypercalcemia revealed parathyroid hormone levels of 152 pg/ml and 25-hydroxy vitamin D of 13.7 ng/ml. He was diagnosed with primary hyperparathyroidism and upon stabilization, discharged with plan for outpatient follow-up. After few months, he had another admission due to worsening epigastric pain. Repeat CT abdomen showed multiple pancreatic lesions involving head, tail and uncinate process and stable adrenal nodules. Presence of pancreatic lesions, gastric ulcers, hyperparathyroidism, adrenal nodules, and multiple skin lesions raised concern of MEN1. Further evaluation showed elevated gastrin level (633 pg/ml), chromogranin level (2464 ng/mL) and mildly elevated prolactin. Rest of pituitary and adrenal axis hormone levels were normal. MEN1 gene testing was positive. No pituitary lesion was identified on magnetic resonance imaging brain. He underwent subtotal parathyroidectomy and cervical thymectomy. He was continued on twice daily pantoprazole and was discharged home in stable condition. MEN1 tumor types and age of tumor onset can differ significantly, and tumors become evident either by hormonal overproduction or by tumor growth. There are no genotype phenotype correlations, even within the same family. Pharmacological therapies to suppress hypersecretion are often first line and can be successful in up to 50% patients. Surgery is an option for patients with hypersecretion unresponsive to medical therapy, compression of the optic nerves and/or chiasma endangering vision or when there is uncertainty of diagnosis requiring biopsy. MEN1 is linked with higher mortality. Approximately 70% of the MEN1 deaths are due to thymic neuroendocrine tumors (NETs) and duodenopancreatic-NETs. Early diagnosis of tumors with appropriate interventions can significantly improve patient survival.