Fatty degeneration in renal tubule epithelium in accidental hypothermia victims

The diagnosis “death due to hypothermia” is mainly based on circumstances and gross autopsy findings like frost erythema and gastric erosions. Up to now, there are no reliable histologic criteria available to confirm the diagnosis “death due to hypothermia.” However, fatty changes of organs have been reported already in the literature as a histological finding contributing to the diagnosis “death due to hypothermia.” To evaluate these reports, cases with well-documented hypothermia (study-group; n=83), cases with other causes of death (control-group; n=25) and additionally also seven cases with a past medical history of diabetes mellitus were investigated. Renal tissue autopsy samples were taken from both the left and the right kidney and investigated for signs of fatty degeneration within the renal tubule epithelium. The results were compared with regard to macroscopic signs of hypothermia (Wischnewski-ulcers, erythema), as reported in the autopsy protocols. The results lead to the conclusion, that fatty degeneration is a very reliable histologic diagnostic criterium in cases of hypothermia, comparable to the significance of Wischnewski-ulcers.