Cytologic atypia associated with microglandular hyperplasia

Although it has long been known that microglandular hyperplasia (MGH) may be associated with cytologic atypia in cervical smears, the cytomorphology of MGH has not been described in great detail. To clarify its cytomorphology, Pap smears obtained from biopsy proven cases of MGH over a 3‐yr period were reviewed. Of 122 smears containing endocervical cells, 34 (28%) showed striking glandular abnormalities. In two cases, adenocarcinoma and adenocarcinoma in situ were falsely suggested and a high grade squamous intraepithelial lesion (HGSIL‐CIN III) was not confirmed in a conization specimen which showed only low grade SIL and MGH. Review of six cytologic diagnoses of HGSIL (CIN III) unconfirmed on biopsy suggested overcalls related to MGH related atypia in five. Cytologic features of MGH, therefore, may occasionally result in erroneous interpretations of HGSIL as well as glandular neoplasia. Although these changes may be striking, comparison with glandular atypia not associated with MGH shows that they are not entirely specific. © 1994 Wiley‐Liss, Inc.