Myometrial smooth muscle neoplasms are the most common gynecologic tumors with a prevalence of 70-80% at age 50. Among women undergoing hysterectomy or myomectomy for a suspected diagnosis of leiomyoma, 0.01% receive a diagnosis of STUMP. Clinically, the average age of presentation is between 41-48 years. Tumors ranging from 3 to 30 cm have been described. Signs and symptoms are similar to leiomyomas, such as abnormal uterine bleeding, anemia, dysmenorrhea, pelvic pain, pelvic mass, infertility or other types of pain secondary to compression of adjacent organs. Due to the limited literature available, there is no definite management consensus, and treatment and follow-up options are limited to observational studies. The standard treatment is total hysterectomy with or without bilateral salpingo-oophorectomy; if fertility has already been completed, there is no role for adjuvant hormonal therapy or chemotherapy. The overall 5-year survival is 92-100%. A case of a 31-year-old woman with STUMP is presented.