Squamous cell carcinoma of the cervix, with extension in an in situ fashion into the endometrium.

A 55-year-old, white, multiparous woman had an invasive, endocervical, squamous cell carcinoma. The tumor had spread superficially into the entire endometrial cavity. The lesion abruptly terminated at the squamocolumnar junction, and the exocervix was free of invasion. Apparently, the cervical, malignant, squamous epithelium had spread upward in a superficial fashion and had mechanically replaced the columnar epithelium.