We report a case of malignant tumor of the stomach showing both carcinoma and sarcoma components in a 47 year-old woman. The resected stomach revealed two tumors which were in different location. The one mass was a 2 x I cm, poorly demarcated tumor at the body, along the lesser curvature and the other was a 6 x 7 cm, well demarcated polypoid tumor with a central depression at cardia of the posterior stomach wall. The tumor at the body was a poorly differentiated adenocarcinoma which showed strong reactivity for CEA. The tumor at the cardia was composed of epithelioid or spindle shaped cells with abundant eosinophilic cytoplasm and revealed 5-6 mitoses per ten high power field. The tumor at the cardia was diagnosed as epithelioid leiomyosarcoma and showed reactivity for vimentin but none for actin, desmin,keratin, and CEA. This is different from the usual carcinosarcoma.
Epithelioid smooth muscle tumor is relatively rare and potentially malignant, especially in retroperitoneum.
Distinct criteria for malignancy still have not been clarified in this epithelioid variant arising in retroperitoneum. We report a deceptively benign-appearing epithelioid leiomyosarcoma in a 50-year-old female. She was admitted with abdominal discomfort and dysuria. Abdominal CT showed a well-demarcated, 10 10 cm sized, solid mass in retroperitoneum. Concomitant metastatic lesions were noted in right lung field. Surgical excision of retroperitoneal mass and right lung lobectomy were performed. The retroperitoneal mass showed yellowish-tan, well-delineated and lobulated appearance. Histologically, this tumor was composed of predominantly epithelioid, round to oval cells with distinct clear cytoplasm and slightly atypical nuclei.
Mitosis was rare (0~1/50 HPF). Lung lesions were morphologically similar to that of retroperitoneum.