ULTRASTRUCTURAL AND IMMUNOHISTOCHEMICAL CHARACTERIZATION OF THE TUNICA ALBUGINEA IN PEYRONIES-DISEASE AND VENOOCCLUSIVE DYSFUNCTION

The tunica albuginea and corpus cavernosum from patients with Peyronie 's disease (PD), patients with veno-occlusive dysfunction (VOD), and t hose from normal control subjects were studied by transmission electro n microscopy and immunohistochemical staining for type I, III, and V c ollagens, platelet-derived growth factor (PDGF) AA and BB homodimers, and PDGF alpha and beta receptors. Ultrastructural modifications resem bling a fibrotic reaction were detected in the two pathological tunica albuginea, but not in those from control subjects. Ultrastructural da ta demonstrated a general increase in fibrous and amorphous extracellu lar matrix material in the pathological tunica albuginea. The amorphou s material probably represents glycoproteins and proteoglycans. The fi brous material, representing collagen, appears disorganized in the tis sue and does not display the typical and homogeneous diameter, size, a nd spatial arrangement. Large areas of extracellular and intracytoplas mic, partially degraded, fibers are visible. An increased type I/III c ollagen ratio was detected by immunohistochemistry in the two patholog ical tunica albuginea. Moreover, a strong expression of type V collage n, correlated to fibroblasts, was revealed. Fibroblasts from control t issues, on the other hand, were totally negative. Finally, PDGF AA and BB were positive in fibroblasts from pathological tunica albuginea bu t were negative in control tissues. PDGF beta receptor was positive in pathological and normal tissue fibroblasts. Tunica albuginea from PD and VOD show similar ultrastructural and immunohistochemical alteratio ns, whereas the corpus cavernosum shows no visible modifications.