An Interesting Case of Melena: Gastric Neuroendocrine Tumor

Abstract

We present an atypical cause of melena secondary to a gastric neuroendocrine tumor successfully managed by endoscopic submucosal dissection (ESD). A 66-year-old male with a history of hypertension, gastritis and peptic ulcer disease presented with three days of melena. EGD showed an ulcerated, protruding mass at the lesser curvature of the stomach. EUS confirmed a hypoechoic, homogeneous mass measuring 16 mm originating from the muscularis mucosa with an intact muscularis propria. ESD was performed with successful en bloc resection of the gastric mass. Pathology revealed a well-differentiated neuroendocrine tumor (NET) without associated atrophic gastritis. The tumor was classified as intermediate grade 2 with a Ki-67 index of 3-4%. Of note, there was involvement of the deep margin in the resected specimen. CT of chest, abdomen, and pelvis showed no evidence of other masses or metastases. Given the positive deep margin, a subsequent EGD with full-thickness resection of the ESD site was performed with the help of an over-the-scope clip. Pathology showed gastric mucosa with chronic focal inflammation, negative for tumor, with no evidence of NET. A post-resection octreotide scan showed no areas of pathologic uptake of radio-labeled octreotide. No complications were encountered during resection and the patient has had no recurrence on follow up surveillance endoscopy. Gastrointestinal NETs are relatively rare tumors, with carcinoid tumors being the most common type. Gastric involvement is rare, representing 7% of all carcinoid tumors within the GI tract. Gastric carcinoids can be divided into 3 types, differing in behavior and prognosis. Type I (>80%) are associated with chronic atrophic gastritis and pernicious anemia. Type II (< 5%) carcinoids are associated with hypergastrinemia due to gastrinomas. Both type I and type II gastric carcinoids are generally indolent with little malignant potential. Type III (20%) carcinoids are sporadic tumors in the absence of any gastric pathology. Type III tumors have a high rate of metastasis and carry a worse prognosis. Due to their aggressive nature, type III tumors are usually treated with partial or total gastrectomy. We report a case of a type III carcinoid tumor that presented with melena due to mucosal ulceration. Our case highlights the successful management of a type III carcinoid tumor with ESD with no signs of recurrence on follow up.Figure: EGD showing an ulcerated, protruding mass with stigmata of recent bleeding at the lesser curvature of the stomach.Figure: EUS showing a hypoechoic, homogeneous mass measuring 16 mm originating from the muscularis mucosa with an intact muscularis propria.Figure: Site of endoscopic submucosal dissection (ESD) with successful en bloc resection of the gastric mass.