A multivariate statistical study to obtain effective criteria to detect well-differentiated adenocarcinoma in endometrial cytology

Consistency in endometrial cytology is relatively poor. This can be partly attributed to generally accepted criteria based on cellular features. The cytological distinction between grade-1 adenocarcinoma and endometrial hyperplasia is more reliant on architectural features than cellular features. We examined statistical criteria based on cytoarchitecture for detecting grade-1 adenocarcinoma in endometrial cytology. Histologically, the study population consisted of 11 cases of grade-1 adenocarcinoma, 6 of atypical endometrial hyperplasia, 16 of endometrial hyperplasia without atypia, and 74 of a normal proliferative endometrium. In each case, all cellclumps were divided into five patterns (tubular; sheet; dilated and/or branched tubular; regular overlapping; atypical). The frequencies of each pattern were submitted to five-variate cluster analysis. The validity and reproducibility of cluster analysis were tested by canonical discriminant analysis and multigroup linear discriminant analysis, respectively. All 107 cases were classified into three groups, A (11), B (36), and C (60), by five-variate cluster analysis. In comparison with this classification and histopathologic diagnosis, group A corresponded to adenocarcinoma, and groups B and C correlated with non-carcinoma. Most cases of atypical endometrial hyperplasia were included in group B. These data suggest that statistical groupings based on cytoarchitecture are useful in the discrimination of grade-1 adenocarcinoma from endometrial hyperplasia and normal tissue. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.