Association of Gastric Sarcina With Malignant Pyloric Stenosis

<i>Sarcina ventriculi</i> (SV) is a Gram-positive cocci that thrives in the acidic stomach environment and may cause gastrointestinal symptoms. A 65-year-old woman with a history of <i>Helicobacter pylori</i> gastritis and diabetes presented with abdominal pain, vomiting, diarrhea, and weight loss. Initial esophagogastroduodenoscopy revealed pyloric stenosis with thickened prepyloric gastric folds, and endoscopic biopsy revealed SV without malignancy. Owing to persistent symptoms, endoscopic ultrasound was done with repeat biopsies and was nondiagnostic. Subsequently, a robotic gastrojejunostomy was done due to persistent gastric outlet obstruction symptoms. Surgical specimens revealed signet ring cell carcinoma. This case highlights the importance of suspecting underlying malignancy in patients with SV and the necessity of comprehensive diagnostic evaluation when endoscopic findings are inconclusive.