Nodular fibrous proliferation (fibrous pseudotumour) of the tunica vaginalis testis. A light, electron microscopic and immunocytochemical study of a case and review of the literature.

A case of nodular fibrous proliferation of the tunica vaginalis testis occurring in a 25-year-old male is described. Electron microscopy and immunocytochemical analysis confirm a fibroblastic origin. The histogenesis of the lesion is considered in the light of the findings and a review of the literature. It is concluded that the lesions known variously as 'fibrous pseudotumour' and 'reactive periorchitis' represent a fibroblastic overgrowth of the genito-urinary tract in response to trauma or infection. Nodular or diffuse fibrous proliferation of the testicular tunica vaginalis is suggested as a unifying terminology for this group of lesions.