LAUSR

There is a wide range of finding endometrial adenocarcinoma (ADCA) in the uterus after a diagnosis of complex atypical hyperplasia (CAH), likely due to a poor diagnostic reproducibility and an inherent heterogeneity in CAH. We evaluated whether histologic subtyping of CAH would help predict ADCA. Our study consisted of 222 cases of CAH diagnosed by endometrial biopsy or curettage. ADCA was seen in 38.3% of these cases at hysterectomy. We divided CAH into 2 subtypes: type A was defined as back-to-back glands in a focus smaller than 2.1 mm, and type B as crowded glands with cytologic atypia but with still-intervening stroma regardless of lesional size. Type A was associated with a significantly higher frequency of ADCA (75.9%) compared with type B (26.2%). Lesions containing neutrophilic/cellular debris showed a higher association of ADCA (60.0%) compared with those without neutrophilic/cellular debris (35.5%). CAH present outside endometrial polyp was associated with a higher frequency of ADCA (42.5%) than that confined to endometrial polyp (19.5%). Within type B cases, lesions greater than 3 mm had a higher association of ADCA (34.3%) than did smaller ones (13.6%). Patients older than 50 years were more likely to have ADCA in the uterus compared with younger women with a preoperative diagnosis of CAH (43.2% versus 28.3%). CAH made on office biopsy showed a higher association of ADCA (46.6%) compared with a diagnosis made on curettage (31.1%). Recognition of these clinicopathological features in CAH may prove useful in predicting the likelihood of ADCA in the uterus.