Sarcina ventriculi: An incidental finding or a byproduct of a more concerning underlying disease?

Sarcina ventriculi is a rare, acid-resistant, carbohydrate-fermenting, Gram-positive bacterium most often reported in the setting of delayed gastric emptying or gastric stasis and obstruction. Its clinical relevance is variable, ranging from incidental colonisation to potentially severe complications such as emphysematous gastritis and perforation. Diagnosis is typically suggested by the characteristic basophilic tetrads on routine hematoxylin-eosin staining. An 81-year-old male presented with a 3-month history of atypical epigastric pain, postprandial vomiting, and general deterioration. Initial laboratory evaluation showed severe anemia and an inflammatory response. Upper gastrointestinal endoscopy revealed a traversable ulcerated, exophytic antral lesion extending toward the greater curvature. Histopathology of multiple biopsies demonstrated a poorly differentiated gastric carcinoma with concomitant Helicobacter pylori infection and S ventriculi identified on hematoxylin-eosin slides. Contrast-enhanced CT confirmed a locally advanced antrum-pyloric tumor with nodal, hepatic, and peritoneal metastases T4N2M1 (according to the eighth edition of the AJCC TNM staging system). The patient received symptomatic management, Helicobacter pylori eradication therapy, and was referred for palliative oncologic care. He died shortly thereafter. The detection of S ventriculi on gastric biopsies should prompt clinicians to actively search for an underlying cause of gastric stasis or obstruction, including malignancy. Management should prioritise treatment of the precipitating condition. Antibiotic therapy for S ventriculi may be considered in symptomatic patients or when complications are suspected, and H pylori should be treated according to standard guideline-based regimens when present.