Rare tumors of the testis and mesothelial proliferation in the tunica vaginalis.

An increasing number of rare testicular tumors have been recognized in the recent years with a wide and heterogeneous spectrum of morphologies. The utility of ancillary studies, including immunohistochemistry, is often limited and is important for the pathologists to be aware of these entities, because they require a comprehensive pathological and clinical approach for an appropriate treatment.