Morphometry and cytophotometric assessment of DNA in smooth-muscle tumors (leiomyomas and leiomyosarcomas) of the gastrointestinal tract.

The difficulties in predicting the biologic behavior of gastrointestinal (GI) smooth-muscle tumors (leiomyomas and leiomyosarcomas) based on the usual criteria of malignancy are discussed. In order to evaluate the prognostic importance of the nuclear DNA content and nuclear dimensions, measurements were performed on Feulgen-stained sections of GI smooth-muscle tumors from 66 patients. The best discrimination between benign and malignant tumors was obtained by using DNA index and tumor size as descriptors in a linear discriminate analysis. This method separated 79% of the benign and 97% of the malignant smooth-muscle tumors. However, as with conventional criteria for malignancy, there remained a group of tumors close to the discriminating line with an indeterminate malignant potential. In an attempt to reduce the number of such indeterminate tumors, future studies will include the use of several descriptors in a multivariate analysis system and the application of flow cytometric studies to all tumors.