Uterine stromal neoplasms: a clinicopathologic and DNA flow cytometric correlation

Twenty-five uterine stromal neoplasms (five stromal nodules and 12 low-grade and eight high-grade stromal sarcomas) were studied to determine the correlation between clinicopathologic features, flow cytometric tumor DNA content and proliferative fraction, and patient outcome. Fifteen of the 20 sarcomas (five of them high grade) were confined to the uterus (stages I and II); the other five (two low grade and three high grade) extended outside the uterus (stages III and IV). Stromal nodules and low-grade sarcomas manifested diploid DNA content and low proliferative index. All stromal nodules and the majority of low-grade sarcomas pursued a benign clinical course. Two cases of low-grade sarcoma ran a malignant course; both patients had high-stage disease. Three of the high-grade sarcomas were diploid and five were aneuploid. All eight neoplasms demonstrated high proliferative index and seven ran a malignant course (four of five were stage I and three of three were stage IV). Three high-grade stage I tumors had a low mitotic rate but a high proliferative index and ran an aggressive course. All high-stage sarcomas were clinically aggressive, irrespective of their histologic classification or DNA characteristics. The proliferative index by flow cytometry may offer an objective adjunct in predicting the aggressive potential of a subset in low-stage neoplasms.