A clinicopathological studies on gastrointestinal leiomyosarcomas, with special reference to prognosis

Twenty-five cases of gastrointestinal leiomyosarcomas were subjected to clinico-pathological studies in an attempt to correlate the prognosis with tumor size, mitosis, cellularity and DNA ploidy pattern. Leiomyosarcomas greater than 5cm in diameter had poorer prognosis. Those with mitotic index larger than 3.0/mm2, cellularity larger than 3.0/0.0004mm2, DNA aneuploidy had poorer prognosis. By multiple regression analysis, mitotic index was useful for the prediction of tumor recurrence in earlier postoperative period, but cellularity, tumor size were useful for the prediction of recurrence in later postoperative period. As for the type of tumor recurrence, hematogenous metastasis was observed in 7 cases, peritoneal dissemination in 2 and local recurrence in 4. Four cases with local recurrence had all hematogenous metastasis. Two cases of gastric leiomyosarcomas developing local recurrence were greater than 10cm in diameter and gastric local resection was done for them. One case was diagnosed benign leiomyoma in the rectum histologically, but after trans-anal tumor resection local recurrence and metastasis to the lung occurred. We must pay attention to the surgical margin and the surface of tumor dissection during of the tumor, especially in larger tumors. Aggressive surgical resection is efficient for the treatment of recurrent tumors.