If the tubular lumens are dilated, the atrophy is likely caused by pressure (i.e. pressure atrophy) fromprolonged and severe tubular dilation (also see ) The change may be unilateral or bilateral and focal, multifocal, or diffuse and occurs as an occasional incidental finding in mice and rats at all ages, with the incidence increasing with age. Germinal epithelial atrophy is an end-stage lesion and is generally preceded, or accompanied by, seminiferous tubule degeneration. Depending on severity, the affected testes may be macroscopically flaccid and reduced in size and weight. Severe, diffuse germinal epithelial atrophy is often irreversible. Scattered seminiferous tubules with germinal cell atrophy can be seen as an aging change in rats.
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