Extrapelvic endometriosis presenting as a retroperitoneal tumor A. Alves * , P. Luís, A. Ribeiro, M. Ferreira * Hospital Santa Maria, Servico de Anatomia Patologica, Lisboa, Portugal Objective: Endometriosis is a benign disease characterized by the presence of functional endometrial tissue in ectopic locations. Retroperitoneal, liver or kidney involvement are extremely rare. Method: We present a case of a 52-year-old woman, which was referred to surgical consultation because of a retroperitoneal mass that was found on a routine abdominal ultrasonography (US). A subsequent CT scan showed a 12 cm tumor involving the liver, right kidney and adrenal gland. The gynecological US revealed ovaries with normal size and two probable uterine leiomyomas. She was submitted to a tumorectomy with segmental hepatectomy and nephrectomy. Results: Grossly, the tumor was 12×8×6 cm, invaded the kidney, the liver and a segment of diaphragm. It was white, fasciculate and with hemorrhagic focus. Histologically the tumor was composed of a biphasic proliferation of endometrial glands and endometrial stroma, both without atypia. The case was diagnosed as deep infiltrating extrapelvic endometriosis. With a 5 years follow-up, the patient is doing well and without evidence of disease. Conclusion: Despite being an extremely rare presentation, endometriosis can involve retroperitoneal organs and simulate a malignant neoplasm, even without a previous history of pelvic involvement. Objective: Malignant melanoma of the female genital tract is a multifocal disease resulting from a disorder of melanocytes Cotyledonoid dissecting leiomyoma is a benign smooth muscle tumor which can mimic a malignant lesion due to its alarming aspect. There are some variant forms of leiomyomas with an unusual infiltrative growth pattern. Due to its worrying appearance of the gross specimen, it is often mistaken for malignant lesion and it is important to be aware of this entity not to over treat this benign smooth-muscle neoplasm. We report a case of a 55 years old woman who underwent hysterectomy because of the suspect of a tumor growing from the right lateral uterine wall. On gross study the tumor measured 10 mm in diameter and was nodular, brown in color and irregular on cut section. Histological examination showed a nodular tumor composed of smooth muscle cells with a storiform pattern which dissects the uterine wall. The tumor was highly vascularized, included a myxoid component and showed some areas with invasion of vascular components. Cellular atypia, mitosis and necrosis were absent. The patient has had a good clinical course, without relapses until the date, what supports the fact that these tumors have a benign clinical behavior, even though they may have a malignant appearance.