MRI features of nipple leiomyoma in a male patient: A case report

Nipple leiomyoma is a benign cutaneous tumor that arises from the smooth muscle fibers of the musculus areolae and represents the rarest subtype of cutaneous leiomyoma. Since its first description by Virchow in 1854, approximately 50 cases have been reported, with only 20 involving male patients. Imaging findings, particularly the MRI characteristics, have been insufficiently documented. We report a man in his 70s with a 10-year history of left nipple pain. Ultrasonography revealed a mildly irregular hypoechoic mass with increased vascularity. MRI demonstrated a well-defined, smoothly marginated mass with intermediate signal intensity on STIR and T1WI, a hypointense rim, and a slow, persistent contrast-enhancement pattern without diffusion restriction. Core needle biopsy confirmed a leiomyoma. The lesion was managed conservatively at the patient's request. Recognition of the MRI characteristics of nipple leiomyoma may help the differential diagnosis of nipple lesions.