Lymph Node Primary Gastrinoma: A Case Report

Abstract

Introduction: Zollinger-Ellison (ZE) syndrome is caused by gastrin-secreting tumors of neuroendocrine origin. Subsequent gastric acid hypersecretion leads to peptic ulcer disease, malabsorption and diarrhea. Here we present a rare case of a lymph node primary gastrinoma.Figure 1Figure 2Figure 3Case report: A previously healthy 55 y/o female presented with chronic heart burn and epigastric pain associated with diarrhea, intermittent melena and unintentional 100 pound weight-loss over 1 year. Proton pump inhibitors (PPI) and histamine receptor-2 blockers did not alleviate her symptoms. No family history of tumors were noted, including those related to multiple endocrine neoplasia type I (MEN-I, Wermer syndrome). Blood labs were normal other than mild normocytic anemia and hypoalbuminemia. Upper endoscopy showed LA grade B esophagitis, as well as multiple ulcers in the second and third portion of duodenum. CT scan did not show any abnormalities, including masses. Given clinical suspicion, gastrin and chromogranin A levels were measured, which were markedly elevated at 2341 pg/mL and 2737 ng/mg, respectively. Octreotide scan showed a foci of activity in the proximity of pancreatic head. Endoscopic ultrasound (EUS) showed a round, hypoechoic 1.3 cm lymph node near the pancreatic head that underwent fine needle aspiration (FNA). On cytology review of smears and cell block, there were monotonous bland cells that stained positive for gastrin, synaptophysin and chromogranin. Gastric fluid pH was measured at this time, while on twice daily oral PPI therapy, and was found to be 2. She then underwent exploratory laparotomy. She was found to have a peri-duodenal lymph node, which was resected and confirmed to have intranodal gastrinoma. No other masses or lesions were identified. There was resolution of her symptoms and hypergastrinemia to 87 pg/mL, and have remained stable for 7 months post-surgery. Discussion: ZE syndrome is a rare cause of hyper-gastrinemia that leads to acid hypersecretion. Typically when a lymph node is involved it represents metastatic disease; however, in this case report we present a rare case of lymph node primary gastrinoma. This is supported by clinical symptoms, EUS findings, correlating octreotide scan, hypergastrinemia with low gastric pH, and the subsequent surgical resection of a lymph node that resulted in the resolution of her symptoms and normalization of her labs.