The pattern of cervical involvement in 107 endometrial adenocarcinomas was assessed. The cervix was involved in 29%, higher than noted in previous studies. In 40.6%, the lesion was confined to surface endocervical epithelium only; the remainder had cervical stromal involvement. In the majority only small areas within the circumference of the cervix were affected, indicating a need for adequate tissue sampling. In some cases, malignant epithelium was found as a "migrant" within the endocervical canal, entrapped within cervical mucus or applied to surface epithelium, supporting the concept that endometrial cancer spreads by surface contiguity or implantation rather than by deep tissue planes or via lymphatic channels. Our findings reinforce the view that high-grade lesions and histological subtypes such as uterine serous papillary carcinoma are associated with a later presentation, higher stage and poorer prognosis. We have identified atypical changes in endocervical epithelium that may be misinterpreted as cervical involvement, particularly in the form of atypical reserve cell hyperplasia with a micropapillary pattern that may reflect a reaction to the presence of tumor. It is our assertion that the presence of tumor "migrants", and not endocervical surface atypia, is an indicator of increased probability of cervical involvement by endometrial adenocarcinoma (P = 0.015).