Perforated rectal cancer with extensive soft tissue gas

Case contributed by Dr Vikas Shah


History of rectal cancer treated with chemotherapy and radiotherapy. Sudden onset groin pain. No trauma. Raised inflammatory markers.

Patient Data

Age: 70 years
Gender: Male

Heavy vascular calcification and multiple surgical clips. No fracture. Gas in the soft tissues around the left femoral head and neck.


CT abdomen, pelvis and thighs

The tissue planes around the rectal mass are poorly defined, with a small volume of fluid at the left lateral aspect. There are locules of free gas around the rectum, extending into the adjacent obturator muscle complex, and throughout the musculature of the left thigh and buttock. Gas is present within the muscles and between the muscles. There is no abnormal fascial enhancement. No other significant acute intra-abdominal findings.

Case Discussion

Perforation of the rectal malignancy has led to the extensive dissemination of gas throughout the adjacent soft tissues, tracking down the left thigh to the level of the knee. The finding of gas within soft tissues on a plain radiograph often raises the possibility of necrotising fasciitis. In this case, the primary cause of the gas is perforation of a gas containing viscus, but secondary infection by gut microbes may lead to necrotising fasciitis. Fascial thickening and enhancement are useful but inconsistent signs on CT in necrotising fasciitis.

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Case information

rID: 56067
Published: 9th Oct 2017
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

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