Leiomyosarcoma is a rare condition so there are relatively few and small case series and no prospective studies to provide clear guidelines regarding management. We report on a case that presents some particularities that further underline diagnostic and treatment difficulties posed by the affliction of such a rare tumor. This is the case of a 43-year-old woman who had a large tumor arising from the uterus, with a spectacular growth rate over a short period. The patient, with congenital spastic tetraparesis and hydrocephalus, came for belly enlargement with rapid increase in size over the previous two months. Physical exam and ultrasound lead to the conclusion of a large abdominal mass. A computed tomography scan showed a mass arising from the pelvis and a large amount of ascites. An exploratory laparotomy was performed and the histopathology report confirmed the diagnosis of uterine leiomyosarcoma. Leiomyosarcoma poses challenging problems regarding histological grading and, due to its rate of growth, real surgical difficulties. Final diagnosis is done by histopathological examination after surgical excision. Frequently, it is late diagnosed when complete removal of the tumor is often impossible.