Superficial endometriosis of the cervix: A source of abnormal glandular cells on cervicovaginal smears

Superficial endometriosis of the cervix, a benign process which may be associated with atypical glandular cells of undetermined significance (AGUS) on cervicovaginal (CV) smears, is becoming increasingly recognized on colposcopic examination. This study details the clinical, cytologic, and histology features of six cases of superficial cervical endometriosis. All CV smears featured atypical endocervical-like columnar cells in sheets and strips as well as cells with endometrial characteristics including solid cohesive, crowded, overlapping glandular groups, loss of cellular polarity, and a frequent ragged "feathered" edge appearance with protruding nuclei, occasional rosette formations, and endometrial stroma. Recognition of endometrial stroma in continuity with groups of cells with these features on CV smears may suggest the diagnosis of this benign condition. However, the cytologic features of endometriosis show sufficient overlap with those of precancerous and cancerous glandular lesions that many of these cases will continue to be diagnosed as "atypical glandular cells."