Comparative cytologic findings of in situ and invasive adenocarcinoma of the uterine cervix.

The cytologic findings in 13 cases of cervical adenocarcinoma in situ (mean age 33.9 yr) were compared with those in 9 cases of cervical invasive adenocarcinoma (mean age 45.7 yr). All diagnoses were confirmed by biopsy. The major differences found were that a necrotic background (66% invasive vs. 0% in situ) and macronucleoli (77% invasive vs. 0% in situ) were more common in invasive cases, whereas associated squamous-cell dysplasia (69% in situ vs. 0% invasive) was more common in in situ cases. Other differences included syncytial tissue fragments with irregular cell borders, frequent cell drop-off, and markedly atypical single columnar cells (or markedly atypical naked nuclei) seen more commonly in invasive cases, whereas monolayer sheets and/or syncytial tissue fragments with smooth borders and rare cell drop-off were more common in in situ cases. Although none of these features is diagnostic individually, in combination they are helpful in distinguishing between in situ and invasive adenocarcinoma. Nine of 13 of the in situ cases showed associated squamous-cell dysplasia. In all nine of these cases, the glandular dysplasia was overlooked or underestimated in severity on original cytologic diagnosis. This suggests that the presence of a squamous lesion may lead to decreased detection of glandular lesions, perhaps because the features of squamous lesions are more well known; thus they are more easily recognized, at the expense of glandular lesions. All invasive adenocarcinomas were identified as carcinoma in the original diagnosis with seven specified as invasive adenocarcinomas.