Schistosomal pelvic floor myopathy contributes to the pathogenesis of rectal prolapse in young males.

PURPOSE: Rectal prolapse is common in young males in Egypt. The role of schistosomiasis in the pathogenesis of rectal prolapse is not clearly defined. The purpose of this work is to study changes in the pelvic floor muscles in patients of rectal prolapse associated with schistosomiasis.

METHODS: This study included 33 male patients with rectal prolapse of whom 27 patients with schistosomiasis and 6 patients free from schistosomiasis. Biopsies were taken from the pelvic floor muscle during surgery. The prepared sections were examined for histopathologic structural changes, for ultrastructural changes (by using electron microscopy) and after immunohistochemical staining by using anti-IgG and anti-IgM antibodies.

RESULTS: The muscles from the patients without schistosomiasis had no histologic or EM changes and showed negative staining for IgG and IgM. Myopathic changes were found in the group of patients with schistosomiasis, including increased variation in the fiber diameter in 66.6 percent of patients, degenerative changes in 59.26 percent of patients, fiber splitting and fragmentation in 44.4 percent of patients, and endomysial fatty changes in 55.5 percent of patients. Ultrastructural study revealed starting loss of striation and margination of the nucleus in 70.37 percent of patients, distorted myofibrillar pattern in 51.85 percent of patients, disturbed endoplasmic reticulum and increased glycogen granules in all patients, the mitochondria are irregularly arranged with electron dense matrix in 40.74 percent of patients, and prominent nuclear sap in 13.72 percent of patients. The muscles of all the schistosomal patients showed a positive cytoplasmic staining for immunoglobulin G, of them only 12 patients showed positive staining for IgM.

CONCLUSION: Patients with schistosomiasis suffer from pelvic floor myopathic changes that may contribute to the pathogenesis of rectal prolapse in young males. The immunohistochemical findings suggest immunologic mechanism for this myopathy.