We present two cases of pyoderma gangrenosum (PG) with unusual histopatholo
gical findings. The main histopathological feature of PG is usually massive
neutrophilic infiltration; the neutrophil is thus the cytologic hallmark o
f PG. The occurrence of vasculitis is controversial. In our patients, in co
ntrast, biopsy specimens revealed extensive granulomatous inflammation with
massive tissue necrosis throughout the entire dermis and subcutaneous tiss
ue and vascular involvement simulating many other granulomatous diseases. H
owever, there was no evidence of systemic disease. Our cases may therefore
represent a histopathologically distinct subset of PG.