Necrotizing fasciitis of the thigh secondary to perforated rectal cancer: the sciatic foramen as a route for infective spread.

Necrotizing fasciitis (NF) is a potentially life-threatening surgical emergency. It is a rapidly progressive infection of soft tissues, and mortality is related to the degree of sepsis and the general condition of the patient. It is a rare condition that requires a rapid diagnosis and surgical treatment is aggressive debridement. There are a small number of reported cases of perforation of a rectal malignancy leading to NF of the thigh. We present a case with rectal cancer in which the sciatic foramen had provided a channel for the spread of pelvic infection into the thigh.