Persistent Müllerian duct syndrome suggested by magnetic resonance imaging.

We report the case of a 45-year-old man with persistent Müllerian duct syndrome suggested by its characteristic appearance magnetic resonance (MR) imaging. A tubular structure extending from the patient's left inguinal region to the pelvic cavity was found incidentally at surgery for a testicular tumor. T2-weighted MR images obtained after surgery revealed the characteristic three-layer structure in the left pelvic cavity with no relation to the bladder or prostate. The hyperintense inner layer, hypointense middle layer, and hyperintense outer layer were thought to represent the endometrium, junctional zone, and outer myometrium of the uterus, respectively. Cryptorchidism and transverse testicular ectopia were not associated. The structure was not resected because there had been no reports of malignancy arising from the Müllerian duct remnant.