Atypical polypoid adenomyoma of the uterus: A reappraisal of the clinicopathological and immunohistochemical features

In this study, we compared the clinicopathological and immunohistochemical features between 36 APAMs and 48 endometrial carcinomas. APAM with a highly complex structure (n = 13) coexisted with atypical hyperplasia (n = 5) and endometrial carcinoma (n = 1). Two patients had endometrial carcinomas at 1 and 102 months. Four patients recurred at 1-57 months but none died of disease. The fibromuscular stroma demonstrated 3 uncharacterized features: a broad bundle (10/36), a lobular structure separated by the stromal branches (26/36), and the extension of fibromuscular stroma underneath the surface epithelium (31/36). However, these features were not seen in endometrial carcinomas except the vaguely lobular pattern. Both APAM and endometrial carcinoma showed a similar immunostaining pattern except high Ki67 index in endometrial carcinomas (p < 0.05). Our study suggests that the distinct features of the fibromuscular stroma can aid in the differential diagnosis between APAM and endometrial carcinoma.
Source: Pathology Research and Practice - Category: Pathology Source Type: research