Mesonephric duct remnants in the ovary are characterized by small clusters of tubules within periovarian tissue (Figure 1 and Figure 2). The tubules are lined by cuboidal to tall columnar epithelium and have an appearance reminiscent of epididymal tubules. These tubules are recognized as being remnants of mesonephric ducts.
Ovary - Mesonephric duct remnant should always be diagnosed but need not be graded.
Dixon D, Alison R, Bach U, Colman K, Foley GL, Harleman JH, Hawarth R, Herbert R, Heuser A, Long G, Mirsky M, Regan K, Van Esch E, Westwood FR, Vidal J, Yoshida M. 2014. Nonproliferative and proliferative lesions of the rat and mouse female reproductive system (INHAND). J Toxicol Pathol 27(suppl):1S-107S.Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4253081/