Primary ovarian leiomyosarcoma, a very rare entity

Primary ovarian sarcoma is a very rare tumor, accounting 1% of all ovarian malignancies. The most common histologic subtypes are: mixed mullerian tumor, stromal cell sarcoma and fibrosarcoma. Primary ovarian leiomyosarcoma is an extremely rare histologic subtype of ovarian sarcomas. Until now, about 66 cases have been reported in English literature. Among them, 43 were primary ovarian leiomyosarcoma without heterologous elements and 23 were primary ovarian leiomyosarcoma with heterologous elements. It is usually occurs in postmenopausal women, although sometimes younger women may be affected. The mean age at diagnosis is 52 years (range 12-84 years). The precise histogenesis of primary ovarian leiomyosarcoma is relative unknown. It is probably originates from smooth muscle present in the walls of the blood vessels in the cortical stroma, in the corpus luteum, in the ovarian ligaments at their point of attachment to the ovary, in remnants of Wolffian ducts and in totipotential cells of ovarian mesenchyme. Most patients with primary ovarian leiomyosarcoma usually have nonspecific symptoms and signs. Also they have pressure symptoms on adjacent organs. Primary ovarian leiomyosarcoma is typically present as a solitary, large, lobular, soft, fleshy, solid mass with hemorrhage and cystic degeneration. It is usually unilateral and may reach more than 10 cm in diameter. The diagnostic criteria for primary ovarian leiomyosarcoma are: hypercellularity, nuclear atypia, pleomorphism, coagulative necrosis and high mitotic activity. Immunohistochemical staining for primary ovarian leiomyosarcoma is generally positive for muscle specific actin, SMA, desmin, vimentin, p53 and proliferation markers and negative for cytokeratins and S-100. Due to the rarity of primary ovarian leiomyosarcoma, it is very difficult to determine the optimal therapy. Surgery is the baseline therapy and complete resection should be attempted whenever possible. Postoperative adjuvant radiotherapy is used for local disease control. Postoperative adjuvant chemotherapy is used in patients with locally advanced or metastatic disease. The prognosis of primary ovarian leiomyosarcoma is generally unfavorable, depending on mitotic activity and stage at diagnosis. Most patients die with extended local disease and multiple distant metastases