Assessment of depth of myometrial invasion in endometrial adenocarcinoma

Depth of myometrial invasion in stage I adenocarcinoma of the endometrium is recognized as a prognostic factor for lymph node metastasis and overall survival. To determine if depth of myometrial invasion estimated by gross examination correlated with final histologic depth of invasion, we retrospectively reviewed all cases of surgical stage I endometrial adenocarcinoma treated at our institution between July 1985 and July 1988. Of the 113 evaluable patients, 63 had grade 1 lesions, 37 grade 2 lesions, and 13 grade 3 lesions. The depth of invasion was accurately determined by gross examination in 55 of 63 (87.3%) grade 1 lesions, 24 of 37 (64.9%) grade 2 lesions, and only 4 of 13 (30.8%) grade 3 lesions. Thus, gross examination of fresh tissue to estimate depth of myometrial invasion in endometrial adenocarcinoma is less reliable as the grade of the tumor increases. Alternative methods, such as frozen section, should be considered when evaluating depth of invasion, especially when this affects intraoperative decisions regarding lymph node sampling.