DNA image cytometry in the differential diagnosis of endometrial hyperplasia and adenocarcinoma

To test the value of DNA image cytometry in the differential diagnosis of hyperplastic endometrial lesions and endometrial carcinoma on a series of 153 cases of simple hyperplasia (n = 71), complex hyperplasia (n = 28), complex atypical hyperplasia (n = 11) and endometrial adenocarcinoma (n = 43).

Monolayer smears were prepared from three 50-micron-thick sections by a cell separation technique and were stained according to Feulgen. The DNA content of 250 epithelial cells, chosen randomly, was determined using a TV image analysis system (CM-1, Hund, Wetzlar, Germany). The DNA content of 30 lymphocytes served as an internal standard for the normal diploid value in every case. Different DNA cytometric parameters and the mean nuclear area were calculated.

Cases of adenocarcinoma and complex atypical hyperplasia (n = 54) were defined as clinically "positive" as these patients are normally treated by hysterectomy. The remaining cases of simple and complex hyperplasia (n = 99) were interpreted as clinically "negative" as conservative therapy is usually preferred. Requesting a specificity of > 90%, high sensitivity rates were calculated for ploidy imbalance (94%), mean ploidy (91%), diploid deviation quotient (91%), DNA stemline ploidy (87%) and 2c deviation index (85%), based on suitable thresholds. Entropy (76%), 5c exceeding events (63%), mean nuclear area (48%) and 9c exceeding events (6%) revealed lower sensitivity values. 5c Exceeding events (P = .0117) and mean nuclear area (P = .0392) were helpful in differentiating between atypical hyperplasia and endometrial carcinoma as the data distribution was significantly different with the U test.

Our results indicate that DNA single cell cytometry is a highly relevant tool in the differential diagnosis of endometrial lesions and could be used as a complementary diagnostic method, especially in histomorphologically difficult cases.