An autopsy case of a homeless person with unilateral lower extremity edema

We present an autopsy case of a homeless person showing remarkable unilateral lower extremity edema, which was strongly associated with the cause of death. A 55-year-old homeless man without any past medical history was found dead in a flophouse. External examination showed evidence of malnourishment and remarkable swelling of the right, lower extremity. Putrefactive discoloration in the same area was evident at the time of autopsy (approximately 30h post-mortem). The autopsy revealed focal pneumonia in the right lower lobe, dehydration and chronic pancreatitis. Dissection of the edematous extremity revealed massive abscess formation in the subcutaneous tissue and superficial fascia around the right knee joint. Histopathological findings were compatible with necrotizing fasciitis and blood chemistry results showed an elevation of HbA1c (6.3%). The cause of death is considered to be necrotizing fasciitis and secondary pneumonia/dehydration. This case suggests that necrotizing fasciitis should be differentiated during postmortem diagnosis, especially in cases showing lower extremity edema with early putrefactive changes. In addition, forensic pathologists should closely examine a lower extremity of such cases to detect a true cause of death, even if other pathological findings which can be a cause of death, such as pneumonia and dehydration, are observed in major internal organs.