Abstract
A rare case of hepatic gas‑forming metastases secondary to Clostridium septicum infection is described. A 78‑year‑old woman was admitted with right lower quadrant abdominal pain and deterioration. Initial imaging revealed a right‑sided colonic malignancy with hepatic metastases. Follow‑up scans showed gas within metastases and minimal pneumoperitoneum, suggesting bowel perforation. However, blood cultures isolated C. septicum, supporting infected necrotic metastases as the source of free gas.
Teaching point: This case emphasizes the importance of distinguishing infectious intratumoral gas from perforation in oncological patients and provides one of the few reports with sequential imaging of this process.