[Determination of cell nuclear DNA content in leiomyoma and leiomyosarcoma of gastro-intestinal tract (G-I)].

Nuclear DNA content was measured by microspectrophotometry in 15 biopsy specimens from patients with G-I smooth muscle tumors (3 leiomyomas and 12 leiomyosarcomas subdivided into 3 groups with 4 cases to each). The mean DNA value increased steadily as follows: leiomyomas (14.39 +/- 0.62 Au); leiomyosarcoma Grade I (19.78 +/- 2.39 Au); Leiomyosarcoma Grade II (26.39 +/- 1.60 Au); leiomyosarcoma Grade III (30.66 +/- 2.39 Au). The difference of DNA value in the 4 groups had statistical significance (P less than 0.05-0.01). These results suggest that microspectrophotometric measurement of nuclear DNA content may serve as an objective quantitative method for diagnosis of G-I tract smooth muscle tumors and classification of leiomyosarcoma.