Histological classification of spermatic cord cysts in relation to their histogenesis.

Light microscopy study of spermatic cord cysts in 26 men revealed three different histological patterns. First, cysts of probable mesothelial origin (14 cases) with an unilocular aspect: their epithelial cells showed poor cohesion and often appeared sloughed; subepithelial hyalinization or fibrin deposits were frequent. Second, cysts of probable embryonal (mesonephric) origin (8 cases): they were usually multilocular cysts and their epithelial cells showed great cohesion: zones of ciliated columnar epithelium associated with embryonal remnants displaying a similar epithelium were often found; the embryonal remnants and the cyst lumen contained spermatozoa in 2 cases. Third, cysts of doubtful origin (4 cases) showing abundant inflammatory infiltrates, which had destroyed the epithelium; the unilocular pattern observed in 3 cases suggests a mesothelial origin for these cysts, while the multilocular pattern and presence of embryonal remnants in the other case suggest an embryonal origin.