Abstract
A 63-year-old man with untreated diabetes visited a local hospital for abdominal pain and was admitted with a diagnosis of cellulitis. He was subsequently transferred to our hospital because his abdominal pain exacerbated. He did not present with muscular guarding, but had necrosis and tenderness in the epigastric region, as well as a subcutaneous abscess in the left side of the trunk. His abdominal computed tomography revealed a large amount of gas in the left side of the trunk, which had caused the abdominal wall all layers in the umbilical left. There was no free gas image and ascites in the abdominal cavity. Debridement was immediately performed under the diagnosis of necrotizing fasciitis. Leading to the umbilical left, feces were discharged. The site of perforation was identified to be the diverticulosis of the sigmoid colon. We had diagnosed necrotizing fasciitis caused by penetration of a sigmoid diverticulum, and performed the Hartmann operation. Here, we thus present a case of necrotizing fasciitis caused by penetration of a sigmoid diverticulum.