Uterine Mesenchymal Tumors

Abstract Uterine mesenchymal tumors are neoplasms derived from or differentiating toward mesodermally derived tissues. Differentiation is typically toward normal constituents of the uterine corpus—endometrial stroma and myometrial smooth muscle. However, differentiation toward heterologous tissues such as skeletal muscle, cartilage, or bone may also be seen. Recent updates on diagnosis and classification in uterine mesenchymal tumors include reclassification of endometrial stromal tumors to include a high-grade endometrial stromal sarcoma and the improved recognition of hereditary leiomyomatosis renal cell carcinoma syndrome–associated smooth muscle tumors.