Exploring the Excluded Territory: A Case of Signet Cell Cancer of the Excluded Stomach

Abstract

Roux-en-Y gastric bypass (RYGB) is one of the most commonly performed weight reduction surgeries. Evaluation of diseases of the excluded stomach such as ulcers or malignancy pose a significant challenge due to difficulty in accessing the excluded portion of stomach. We report a case of gastric cancer of the excluded stomach diagnosed using advanced endoscopy techniques. A 40-year-old female with Roux-en-Y gastric bypass surgery performed 13 years ago for morbid obesity presented with epigastric pain and weight loss. She was recently diagnosed with bilateral metastatic signet cell carcinoma of the ovaries for which she was on chemotherapy. Her family history was significant for gastric cancer in maternal aunt. Abdominal computerized tomography (CT) was unremarkable. Esophagoduodenoscopy failed to examine the excluded stomach due to limited length of scope and was otherwise normal. Colonoscopy was unremarkable. The excluded stomach was subsequently approached using antegrade double balloon enteroscopy (ADBE) via afferent limb of Roux-en-Y bypass. A large infiltrative ulcerated circumferential mass was found in the prepyloric region and antrum of the stomach. Biopsies were negative for H. pylori infection and revealed invasive signet cell gastric adenocarcinoma that likely had metastasized to the ovaries. Gastric cancer is the fifth most common malignancy worldwide and the fourth leading cause of cancer-related deaths. RYGB is associated with a 4-fold reduction in incidence of gastric cancer in animal models. Tinoco et al reported the incidence of gastric cancer in the excluded stomach to be 0.03% among 3047 patients who underwent bariatric surgery. However, larger prospective studies are lacking regarding incidence of cancer in this population. Risk factors for gastric cancer include H. pylori infection, smoking, high-salt intake, family history of stomach cancer, obesity and a diet low in fruits and vegetables. Symptoms are non-specific like anorexia, epigastric pain, anemia and weight loss following a period of stability or weight gain. Minimal invasive techniques which can be used to evaluate the excluded stomach are ADBE, percutaneous endoscopy, virtual gastroduodenoscopy, laparoscopic transgastric endoscopy and endoscopic ultrasound (EUS). Patients with prior RYGB presenting with alarming, new onset, unexplained symptoms should prompt evaluation including adequate visualization of the excluded stomach with imaging and advanced endoscopic techniques.Figure: showing postoperative anatomy of modern RYGB.Figure: showing endoscopic view of Infiltrative ulcerated mass in prepyloric region and antrum of stomach (black arrow).Figure: Histopathology slide showing signet cell gastric adenocarcinoma (black arrow).