Difference in cytoplasmic localization pattern of neutral mucin among lobular endocervical glandular hyperplasia, adenoma malignum, and common adenocarcinoma of the uterine cervix

To investigate whether the cytoplasmic localization pattern of neutral mucin differs between lobular endocervical glandular hyperplasia (LEGH) and cervical adenocarcinoma (CxAd), including minimal-deviation adenocarcinoma (MDA), or adenoma malignum, alcian blue (pH 2.5)/periodic acid-Schiff (AB-PAS) staining was performed to formalin-fixed paraffin-embedded tissue sections of 13 lesions of LEGH and 53 tumors of CxAd, including 6 tumors of MDA. The cytoplasmic localization of neutral mucin was classified as a “whole cytoplasmic pattern,” in which neutral mucin filled the cytoplasm entirely, or as an “apical pattern,” in which neutral mucin was localized in the subsurface area only. Cytoplasmic neutral mucin patterns were detected in all 13 cases of LEGH and in 19 cases (36%) of CxAd, including five cases of MDA. The localization of neutral mucin was always the whole cytoplasmic pattern in 13 cases of LEGH, but was the apical pattern in these 19 cases of CxAd. The other 34 cases of CxAd, including 1 case of MDA, corresponded to the acid mucin pattern stained purple or blue or no staining pattern by AB-PAS. Among the 53 cases of CxAd, the apical neutral mucin pattern was an indicator of poorer patient prognosis by univariate and multivariate analyses. The examination of cytoplasmic localization of neutral mucin might be applicable, not only to differential diagnosis between LEGH and CxAd, including MDA, but also to estimate clinical aggressiveness of CxAd.