Abstract:Patients with uterine leiomyosarcoma (LMS) typically present with vaginal bleeding, pain, and a pelvic mass. Typical presentations with hypercalcemia or eosinophilia have been reported. Radiographic evaluation with combined positron emission tomography/computed tomography may assist in the diagnosis and surveillance of women with uterine LMS. A recently developed risk-assessment index is highly predictive of disease-specifi c survival. Ovarian preservation does not appear to negatively impact outcome, and the addition of adjuvant therapy after surgical treatment does not seem to improve survival. It is noteworthy that LMP2-defi cient mice exhibit spontaneous development of uterine LMS with a disease prevalence of ∼37% by 12 months of age. The LMP2 gene is transcribed from a promoter containing an interferon (IFN)-γ-response factor element; thus, the IFN-γ-signal strongly induces LMP2 expression. Furthermore, a recent report demonstrated the loss of ability to induce LMP2 expression, which is an interferon (IFN)-γ-inducible factor, in human uterine LMS tissues and cell lines. Analysis of human uterine LMS shows somatic mutations in the IFN-γ signalling pathway, thus the loss of LMP2 induction is attributable to a defect in the earliest steps of the IFN-γ signalling pathway. The discovery of an impaired key cell-signalling pathway may provide new targets for diagnostic approaches and therapeutic intervention.