Endometrial endometrioid adenocarcinoma: A pathologic analysis of 827 consecutive cases

We reviewed 827 consecutive cases of pure endometrial endometrioid adenocarcinoma (EEA) treated by hysterectomy to update the distribution of pathologic features. Tumor grade (reported in a 2-tiered system), depth of myometrial invasion, presence of cervical involvement, lymphovascular invasion (LVI), and evidence of extrauterine disease were recorded. The median age at diagnosis was 62 years (range, 30-94 years). The tumor was high grade in 94 cases (11.4%), invaded into the outer half of the myometrium in 249 (30.1%), was positive for cervical involvement in 171 (20.7%), and was positive for LVI in 182 (22.0%). Lymph nodes (sampled in 85 cases) were positive in 13 (1.6%), and ovarian metastases were present in 15 cases (1.8%). High tumor grade was significantly associated with deep myometrial invasion (P < .0001), cervical involvement (P = .0065), and LVI (P < .0001). EEA manifests most commonly with low tumor grade and without deep myometrial invasion. High tumor grade is significantly associated with deep myometrial invasion, cervical involvement, and LVI.