Uterine Adenosarcoma with Low Grade Overgrowth and Smooth Muscle Differentiation Mimicking Leiomyosarcoma

Background: Adenosarcoma is a rare mixed mesodermal tumor of the uterus which is composed of benign glandular epithelium and malignant mesenchymal stroma. Case Presentation: 59-year-old postmenopausal women, presented with vaginal bleeding. Per vaginal examination showed a whitish polypoid mass protruding through the cervix which appeared to originate from the uterine body. Magnetic resonance imaging (MRI) revealed an intravaginal polypoid tumor originating from the lateral wall of the uterus. The biopsy from the polypoid mass revealed a leiomyosarcoma. Therefore, the patient underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy. The histological examination revealed a biphasic tumor composed of benign and dilated endometrial glandes and malignant mesenchymal components which were composed of fascicles of spindle shaped cells with mild to moderate nuclear atypia and many mitosis. There are with areas of periglandular cuffs made by small round cells around glands. Immunohistochemical stains were performed and showed that round cells were positive for CD10, while spindle shaped cells were stained with AML and desmine. Histopathological final diagnosis was adenosarcoma with low-grade sarcomatous overgrowth and extensive smooth muscle differentiation. The patient has no evidence of disease, and she is doing well 18 months after the surgery. Conclusion: We report a rare case of Uterine adenosarcoma with low gradeovergrowth and smooth muscle differentiation mimicking leiomyosarcoma