Thirty-eight cases of cervical adenocarcinoma in situ (ACIS) were studied to see if the topography of the ACIS and any stromal invasion by adenocarcinoma were associated with the presence (22 cases) or absence (16 cases) of squamous cervical intraepithelial neoplasia (CIN). Neither the topography of the ACIS (proximal linear extent, focality, presence of ACIS beneath the transformation zone, and circumferential extent) or the presence of invasive adenocarcinoma was associated with the presence or absence of CIN. We conclude that the course of ACIS, at least as reflected by cervical topography and invasive potential, seems to be unaffected by the coexistence of squamous neoplasia.