Sciatica as the first manifestation of a leiomyosarcoma of the buttock

We report the case of a 22-year-old woman who was admitted for inflammatory right-sided sciatica with a decline in general health. Laboratory tests showed severe inflammation. Ultrasonography and computed tomography of the buttock and pelvis demonstrated a large tumor in the deep muscles of the right buttock, with an intrapelvic component that displaced the pelvic organs without invading them. Histologic examination of a biopsy specimen taken via the buttock established the diagnosis of leiomyosarcoma. Surgery by a pelvic approach allowed partial resection of the tumor, which was seen to invade the sciatic nerve. Radiation therapy was given. Six months later the residual tumor was considerably larger and the patient's general health had deteriorated further. Leiomyosarcomas are rare tumors whose diagnosis rests on histologic examination of biopsy or surgical specimens. The treatment is surgical. Recurrences are seen in 40 to 60% of cases, and metastases in 27 to 60%. The place of radiation therapy and chemotherapy in the treatment of leiomyosarcoma remains unclear.