ABSTRACT
OBJECTIVE: To investigate the clinicopathologic features and immunophenotype of endometrial stromal sarcoma (ESS) and extra uterine endometrial stromal sarcoma (EESS). METHODS: 14 cases of ESS (8 cases of ESS and 6 cases of EESS) were retrospectively reviewed, and the pathological features, immunophenotype and prognosis were discussed. RESULTS: In 14 cases of ESS, 12 cases (8 cases of ESS and 4 cases of EESS) were diagnosed as low grade endometrial stromal sarcoma (LGESS) and 2 cases of EESS were diagnosed as high grade endometrial stromal sarcoma (HGESS). Microscopically, the tumor cells in LGESS cases were composed of densely arranged endometrial stromal cells with a similar proliferative phase. They were surrounded by spiral arterioles and mitosis was rare. The tumor cells in HGESS cases displayed marked cellular atypia, increased mitosis, infiltration, and necrosis. However, small blood vessels which were common in LGESS were rarely observed in HGESS. Immunohistochemical results showed that most tumor cells were positive for CD10, vimentin, PR, and ER. CONCLUSIONS: ESS is a rare tumor in the female genital tract and is often misdiagnosed as other mesenchymal tumors before operation. The diagnosis mainly depends on the clinicopathologic features together with the immunophenotype. LGESS has better long term survival and lower incidence of disease recurrence than HGESS. Thus, LGESS has better prognosis than HGESS.
