Comparative study on the nuclear DNA content of leiomyoma, leiomyoblastoma and leiomyosarcoma of the stomach and small intestine.

The nuclear DNA content of tumor cells in 5 leiomyomas, 4 leiomyoblastomas and 2 leiomyosarcomas of the stomach and 1 leiomyosarcoma of the small intestine was examined. From the viewpoint of nuclear DNA content, leiomyoblastoma was between leiomyoma and leiomyosarcoma. A definite difference in nuclear DNA content exists among leiomyoma, leiomyoblastoma and leiomyosarcoma, and percentage of nuclei with a DNA content of 3 times or 4 times over the basic chromosome content represented good indices for distinguishing between benign and malignant conditions. A diagnosis of leiomyocarcinoma may be more accurate when over 80% of the nuclei have DNA content values over 3 times of basic nuclear DNA content and when over 50% exhibit more than 4 times of basic content.