Quantitative analysis of nuclear distribution pattern differentiating carcinoma from hyperplasia in endometrial...

A method of quantitatively analyzing the distribution pattern (DP) of nuclei was introduced and applied to the differential diagnosis between hyperplasia and carcinoma in endometrial cytology. The DP of nuclei can be defined mathematically by [formula: see text] (DP index), where r is the mean distance between nearest nuclei and n0 the number of nuclei per unit area. The DP index has a limited range of decreasing values from 1.074 to 0.5, indicative of regular to random patterns of nuclear distribution. The estimated DP index (mean +/- standard deviation) was 0.826 +/- 0.029 in 23 normal cases, 0.735 +/- 0.019 in 17 cases of adenomatous and atypical hyperplasia, and 0.636 +/- 0.042 in 18 cases of well-differentiated adenocarcinoma. The DP index was significantly different between these three conditions (P less than 0.01). This result indicates that the endometrial epithelial cells lose their normally regular arrangement in the development of neoplastic change, approaching a random arrangement. Quantitative detection of this architectural change with the use of the DP index can facilitate differential diagnosis between hyperplasia and adenocarcinoma in cytologic specimens of the uterine corpus.