Testis, Seminiferous Tubule - Vacuolation

Seminiferous tubule vacuolation can be microvacuolar or macrovacuolar in appearance. Microvacuolation generally occurs in the basal Sertoli cell cytoplasm (Figure 1, arrows), and macrovacuolation appears as one or a few vacuoles within the depth of the seminiferous epithelium (Figure 2, arrows). In most cases, the vacuoles are within or between Sertoli cells. They may contain fluid or lipid, or they may represent dilation of endoplasmic reticulum or intercellular spaces. Ultrastructural studies can be helpful to determine their origin. Vacuolation of Sertoli cells is a common early feature of morphologic injury to Sertoli cells that may be seen in studies of 28 days or less duration, prior to any germ cell degeneration. Alternatively, vacuoles often accompany generalized germinal cell degeneration/atrophy, where they probably represent spaces left by the missing germ cells. Vacuoles can often be seen as an incidental finding in occasional tubules in control testes (Figure 2, arrows) and may increase in incidence and/or severity over time.