Microinvasive adenocarcinoma of the cervix: a cytohistopathologic study of 40 cases

Cervical smears obtained from 40 women with a histologic diagnosis of microinvasive adenocarcinoma (MIA) were reexamined for features of invasion. In our study MIA was defined as stromal invasion by adenocarcinoma cells to 5 mm or less beyond a surface epithelium and without lymphovascular involvement. In 24 cervices, squamous carcinoma in situ was a coincidental histologic finding. All 40 smears contained atypical glandular cells (AGC) forming pseudosyncytial clusters, and 12 showed additional features suggestive of invasion; pleomorphic nuclei, coarse irregular chromatin, karyorrhectic nuclei, and cell detritus. The invasive features tended to occur together and were found more than twice as frequently in this group than in the remaining 28 smears. There was little difference between the two groups in the frequency of super-crowded cell clusters, acini, cell strips, isolated cells, nuclear hyperchromasia, macronucleoli, or normal cervical glandular cells. Fourteen smears from the 24 cervices with squamous carcinoma in situ contained cells from a high-grade squamous intraepithelial lesion. It is concluded that cervical cytologic examination has a sensitivity of 30% (12/40) for the identification of stromal microinvasion in adenocarcinoma in situ. Cell detritus, present in 5/12 smears, is considered highly specific for invasion but lacks sensitivity. Due to the more proximal location and ease of sampling, cytologic examination has a sensitivity of 58% (14/24) for histologically confirmed coexisting squamous lesions.