Myxoid leiomyosarcoma of the stomach: a case report

A case of myxoid leiomyosarcoma of the stomach which developed in a 53-year-old man is reported. The tumor was localized mainly in the greater omentum and was directly connected to the muscle layer of the stomach. No direct invasion to adjacent organs, peritoneal disseminations or distant metastases were noted. Histologically, the tumor prominently comprised a myxomatous lesion with a cellular area portion. The tumor cells had a bipolar or multipolar shape with oval or elongated nuclei, and were scattered in the myxoid stroma which was rich in hyaluronic acid. The cellular area showed a fascicular tumor cell arrangement and also contained pleomorphic tumor cells with abundant mitoses. Immunohistochemically, the tumor cells were positive to vimentin and weakly positive to desmin. Ultrastructurally, pinocytotic vesicles and cytoplasmic microfilaments with focal densities were found in the tumor cells. It is considered important to differentiate between the diagnosis of myxoid leiomyosarcoma and that of any other myxoid malignant tumor.