Electron Microscopic Study of the Penile Plaques and Adjacent Corpora Cavernosa in Peyronie's Disease

BACKGROUND: We conducted ultrastructural studies to clarify the fine structure of penile plaques and adjacent corpora cavernosa, and the causative basis for the process, in Peyronie's disease. METHODS: Penile plaques and adjacent corpora cavernosa were obtained during surgical extirpation from 5 patients with Peyronie's disease. Control tissues from the tunica albuginea and adjacent corpora cavernosa were obtained at penile amputation from 2 patients with penile cancer. Prepared tissues were examined by using electron microscopy. RESULTS: Penile plaques were composed of collagen fibrils, amorphous particulate material, and fibroblasts in all patients. In 1 of 5 patients, myofibroblasts were found in the border area between the lesion and underlying structures. Smooth-muscle cells and endothelial cells resembling myofibroblasts were noted in adjacent corpora cavernosa. In this patient, the plaque progressively enlarged, and was removed within 1 year of onset of the induration. CONCLUSIONS: Fibromatosis in Peyronie's disease involves both fibroblasts and myofibroblasts, which undergo sclerosis in some phase. In addition, smooth-muscle cells and endothelial cells in the adjacent corpora cavernosa may be incorporated in the fibromatosis.