Induratio penis plastica - Morphological, immunohistochemical and cytogenetic findings

In Peyronie's disease, or penile induration there is an underlying prolifer ation of fibroblasts that lead; to scarring in the form of fibrotic plaques and may be accompanied by ossification. The study desribed was undertaken to determine the immunphenotype of the cells involved, and to look for a po ssible cytogenetic connection with the aggressive fibromatoses. Immunohisto chemical staining with a broad spectrum of antibodies and fluorescence in s itu hybridization with a probe against chromosome 8 were undertaken. Immuno staining revealed reactivity of the fibroblasts for vimentin and various co llagens. Foci of fibroblasts that expressed smooth muscle actin were also f ound. A small proportion of the fibroblasts was positive for CD68. Reactivi ty for Factor XIIIa and CD34 was seen only in occasional cells. Many trypta se-positive mast cells were noted. Trisomy 8, which is often seen in the ag gressive fibromatoses, was not found. The findings show that the antigens e xpressed by the cells involved in the development of Peyronie's disease are mainly those typical of fibroblasts. Myofibroblast differentiation is also seen. Unlike in other diseases accompanied by fibrosis (e. g., chronic lym phedema), there is little expression of antigens not typically expressed by fibroblasts. On the basis of the morphological, immunohistochemical, and c ytogenetic findings, Peyronie's disease can be classified as a type of supe rficial fibromatosis.