Demonstration of needle-shaped hepatic inclusions in porphyria cutanea tarda using the ferric ferricyanide reduction test.

In 18 of 19 biopsy and 2 of 3 autopsy samples of hepatic tissue from cases of porphyria cutanea tarda needle-shaped cytoplasmic inclusions are capable of reducing ferric ions in the ferric ferricyanide reduction test. Thanks to the resulting Turnbull's Blue the inclusions are clearly visible, which facilitates their histological demonstration. In 20 biopsy and 20 autopsy samples of hepatic tissue from cases other than porphyria cutanea tarda the inclusions are not present. These needle-shaped inclusions are thus considered to be a specific histological feature. The ferric ferricyanide reduction test represents a simple method for their visualization, which can be used in routine diagnostic practice.