The present report describes a rare case of a uterine perivascular epithelioid cell tumor (PEComa) arising from a polypoid adenomyoma. The patient, a 44-year-old woman with tuberous sclerosis, was incidentally found to have a uterine mass with malignant-appearing features on a computed tomography (CT) scan. Pathological examination of the hysterectomy specimen demonstrated that the tumor was composed of pale, spindle-shaped, epithelioid tumor cells which were positive for SMA and HMB-45. These findings were consistent with a PEComa arising from a polypoid adenomyoma.