S6321 Gastric Glomus Tumor Presenting as Severe Epigastric Pain: A Rare Case Report

Introduction: Gastric glomus tumors are rare, benign mesenchymal tumors. Though often asymptomatic, patients with these tumors can also present with significant epigastric pain. Due to risk of malignant transformation, glomus tumor should be considered in the differential diagnosis of subepithelial lesions found on upper endoscopy. Case Description/Methods: A 38-year-old African American man with no significant medical history presented with a 2-month history of severe, diffuse abdominal pain, predominantly in the epigastric region. The pain, described as “excruciating”, was associated with nausea and constipation. He reported 2-3 bowel movements per week despite drinking plenty of water and taking a high fiber diet. He also endorsed occasional rectal bleeding but denied unintentional weight loss. Abdominal x-ray showed moderate stool burden. The patient was advised to take polyethylene glycol. Due to persistent abdominal pain, he underwent bidirectional endoscopy. Colonoscopy showed medium sized internal hemorrhoids, but was otherwise normal. Esophagogastroduodenoscopy (EGD) revealed a 3-4 cm subepithelial lesion along the greater curvature of the stomach. Abdominal computed tomography (CT) scan showed a hyper-vascular mass, suspicious for a gastrointestinal stromal tumor or neuroendocrine tumor. Endoscopic ultrasound showed a hypoechoic lesion, originating from the muscularis propria. Fine-needle aspiration confirmed the diagnosis of a glomus tumor with histomorphology demonstrating epithelioid cells and immunostain positive for DOG1, synaptophysin, SMA, Calponin. The patient underwent laparoscopic partial gastrectomy, and the tumor was successfully resected. His postoperative course was uneventful, and he advanced to a soft diet on postoperative day 3. On follow up, he reported significant improvement in abdominal pain. Discussion: Gastric glomus tumors are a rare but important diagnostic consideration in patients with severe epigastric abdominal pain. Surgical resection remains the mainstay of treatment. While these tumors are typically benign, careful pathological evaluation is essential due to the possibility of malignant transformation. Long-term surveillance is recommended due to risk of recurrence.