Abstract
BACKGROUND: Enterocutaneous fistula (ECF) is an abnormal communication between the skin and the gastrointestinal tract and is associated with considerable morbidity and mortality. To diagnose ECF, X-ray fistulography and abdominal computed tomography (CT) with intravenous or oral contrast are generally used. If the anatomic details obtained from CT are insufficient, CT fistulography may help diagnose and determine the extent of the abnormal channel. However, CT fistulography is seldom performed in patients with insufficient evidence of a fistula. CASE SUMMARY: A 35-year-old man with a prior appendectomy presented with purulence over the abdominal wall without gastrointestinal tract symptoms or a visible opening on the abdominal surface. His history and physical examination were negative for nausea, diarrhea, muscle guarding, and bloating. Local abdominal tenderness and redness over a purulent area were noted, which led to the initial diagnosis of cellulitis. He was admitted to our hospital with a diagnosis of cellulitis. We performed a minimal incision on the carbuncle to collect the pus. The bacterial culture of the exudate resulted positive for Enterococcus sp. ECF was thus suspected, and we arranged a CT scan for further investigation. CT images before intravenous contrast administration showed that the colon was in close contact with the abdominal wall. Therefore, we conducted CT fistulography by injecting contrast dye into the carbuncle during the CT scan. The images showed an accumulation of the contrast agent within the subcutaneous tissues, suggesting the formation of an abscess. The contrast dye tracked down through the muscles and peritoneum into the colon, delineating a channel connecting the subcutaneous abscess with the colon. This evidence confirmed cecocutaneous fistula and avoided misdiagnosing ECF without gastrointestinal tract symptoms as cellulitis. The patient underwent laparoscopic right hemicolectomy with re-anastomosis of the ileum and transverse colon. CONCLUSION: CT fistulography can rule out ECF in cases presenting as cellulitis if examinations are suggestive.