The groupings occur in small sheets and tighter 3-dimensional clusters. Some mucin is noted within the glandular lumens. In the papillary regions, there are delicate long fibrovascular cores with crowded pseudostratified nuclei and frequent mitotic figures. No solid non-glandular areas are noted. No squamous differentiation is noted.
Endometrial adenocarcinoma is the most common invasive gynecologic malignancy.
The incidence has peaked in the mid-1970's and fallen again to levels reflective of the 1950's. The pattern of incidence in history closely parallels the use of unopposed estrogens. Endometrial cells in a pap smear can be cytologically normal, atypical, or malignant. It is important to recognize the presence of endometrial cells of any type in the post-menopausal woman. They are usually seen in a background of a high degree of squamous maturation.