(620) Chilaiditi Sign in a Case of Fulminant Clostridium difficile Colitis

Introduction: Toxic megacolon is a complication of fulminant clostridium difficile infection (CDI) most commonly seen on imaging as greater than 6 cm dilation of the transverse colon. This extreme colonic dilation may lead to Chilaiditi’s sign, a rare radiological finding in which the bowel is interposed between the diaphragm and the liver. This is often mistaken for pneumoperitoneum or diaphragmatic hernia. Herein, we present first reported case of a patient with toxic megacolon and Chilaiditi’s sign.

Description: A 74-year-old woman with history of coronary artery disease and type II diabetes mellitus presented to the emergency department of a critical access hospital with three days of diarrhea, and abdominal pain. Labs were notable for a leukocytosis with a neutrophilic shift and a metabolic acidosis with a lactate of 5.4mmol/L. CT abdomen was concerning for toxic megacolon. She was transferred to a level-one trauma center for surgical evaluation.
Upon arrival, the patient was noted to be in shock requiring pressors. She was tachycardic with a heart rate of 120 bpm, and tachypneic. Physical exam revealed decreased right basilar breathing sounds, distended abdomen with diffuse tenderness to palpation without peritoneal signs. She received fluid resuscitation and was started on empiric antimicrobial treatment for CDI. Review of outside imaging showed ascending and transverse colon dilatation and bowel looping along the hepatic flexure. It was difficult to discern if bowel was herniating through the diaphragm. Her clostridium difficile testing came back positive. The patient underwent urgent exploratory laparotomy that revealed significantly dilated ascending and transverse colon with the latter tethered above the liver by adhesions.10-15cm of ischemic colon were identified. There was eventration of right hemidiaphragm without evidence of herniation. She underwent total colectomy with small bowel resection and end ileostomy. Her shock gradually resolved post-operation.

Discussion: Chilaiditi sign is a rare radiologic finding in which the bowel is interposed between the liver and diaphragm causing a lucency superior to the liver and can be mistaken for pseudo-pneumoperitoneum or diaphragmatic hernia. To our knowledge, this is the first reported case of Chilaiditi sign in the setting of fulminant CDI.