Introduction: Uterine leiomyosarcoma is a rare cause of abnormal uterine bleeding (AUB) that should be suspected in the menopausal transition stage. Unusually, it is diagnosed incidentally in myomectomy/hysterectomy specimens, a fact that stresses the patient and darkens the prognosis.The best prognosis involves complete surgical removal of the tumor confined to the uterus. Clinical case: We present a late recurrence of leiomyosarcoma originating from a leiomyoma where the differential diagnosis was difficult from the beginning. Complete removal of the tumor required partial ureteral resection (preoperatively inadvertent compromise) and reimplantation using psoas hitch procedure. Conclusion: Not all AUB due to smooth muscle tumor originate from leiomyoma. Incorporation and complementary analysis (via 3D rendering and reconstruction) of computed tomography (CT), magnetic resonance imaging, or CT combined with positron emission tomography can help identify less common entities, preoperative planning, and anticipate management of potential complications.The pathological characterization of the different forms of tumors originating in the smooth muscle requires specialist pathologists and the incorporation of molecular study to classic pathology, to typify the entity and identify new therapeutic alternatives, beyond the surgery more precisely.