STUMP (smooth muscle tumor of uncertain malignant potential) are smooth muscle tumors that cannot be diagnosed as either benign or malignant due to their morphological characteristics. We here report the case of a 44 year old patient with no notable medical history presenting with an increase in the abdominal volume. Pelvic ultrasound and CT TAP scan were performed showing voluminous mass with tissue and fluid-filled component in the uterus. The patient underwent exploratory laparotomy during which two masses were detected, one in the uterus and the other in the retroperitoneal area. Anatomopathologic examination showed uterine myoma associated with a STUMP.