[Gastrointestinal smooth muscle tumors: a study of DNA content and the association with clinicopathology].

Quantitative analysis of DNA content and ploidy pattern was performed in 84 cases of smooth muscle tumors of the gastrointestinal tract by flow cytometry, and the results were correlated with histopathologic features. The aneuploid rate was found to be 0, 50%, 75%, 92.8% and 100% respectively in the tumors with mitotic figures of 0,1, 2-4, 5-9, or over 10/10HPF (P < 0.005), as to be 3.2%, 60%, 95.8% and 100% in tumors with zero, mild, moderate or severe cellular atypia (P < 0.005). There were no aneuploidy in the 30 cases of leiomyomas, but all 40 cases of leiomyosarcomas were aneuploidy, while in the 14 potentially malignant smooth muscle tumors, there were 4 cases of aneuploidy (P < 0.01). The aneuploid rate was significantly higher in tumors with contiguous organ inveasion or distant metastasis (79.5%), and in tumors of large size (64.5%) as well as in tumors with center necrosis (68.3%). 5 year survival rate in patients with aneuploid tumors (41.6%) was significantly lower than those with diploid tumors (96%) (P < 0.005). The results suggested that DNA content and ploidy pattern be used as an objective parameter to distinguish malignants from benigns and predict the prognosis of patients with gastrointestinal smooth muscle tumors.