Remnants of the mesonephric duct (Figure 1) appear as coiled or branching tubules lined by pseudostratified columnar epithelium and smooth muscle and are reminiscent of that seen in the ductus epididymides and vas deferens. Typically these structures are seen laterally attached to the uterine horns or body, and they may be unilateral or bilateral. They are typically present at the site of attachment of the broad ligament of the uterus. These embryonic remnants must be differentiated from neoplasms, which display growth patterns characteristic of the tumor type.
Uterus - Mesonephric duct remnant should be diagnosed but need not be graded unless grading would help characterize a treatment effect.
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