Abstract

Although myxoid change is known to occur in smooth muscle tumors of benign or unspecified nature, leiomyosarcomas have rarely been mentioned in differential diagnosis of sarcomas with myxoid features. To date about six cases have been reported in the literature. This case report is of a 51-year-old woman whose uterus was found to contain a submucosal polypoid mass of myxoid leiomyosarcoma. It is believed to be the first recorded case of myxoid leiomyosarcoma of the uterus in Korea. Grossly, the uterine cavity was filled with a large polypoid mass originating from right lateral wall of fundus. The mass was 5×2.5m in cross and characterized by a gelatinous appearance and an apparently circumscribed border. On microscopical examination, However, it was observed to invade adjacent myometrium and contained copious amounts of myxomatous stroma. Although it was difficult to establish the nature of the neoplastic cells in some areas of these tumor, both light microscopial and histochemical examination showed characteristic features of smooth muscle cells in other areas. The mitotic count was 9/10 high-power-fields. The reported cases of myxoid leiomyosarcoma were those of recurrent lesions within 6 months to 10 years after surgical resection and had average mitotic numbers of 0-2/10HPF. To diagnose this case, mitotic count of 9/10HPF was helpful.