5533 Background: Endometrial cancer is the most common pelvic gynecological malignancy. The diagnosis of well-differentiated endometrial adenocarcinoma, atypical hyperplasia, and marked hyperplasia is often challenging. We sought to investigate the utility of chromosomal anomalies for the detection of uterine endometrial carcinoma using multitarget fluorescence in situ hybridization (FISH). Methods: Samples were collected by endometrial brush and processed by liquid-based thin-layer cytological preparation protocol. For study, we collected cytology slides from consecutive cases to include 50 benign, 50 hyperplasia without atypia, 50 atypical hyperplasia, and 50 endometrial cancers. Each was hybridized using fluorescence labeled DNA probes to chromosomes 1, 8, and 10 (UteroFISH). The FISH signals were enumerated in 100 cells per case, and the chromosomal anomalies were correlated with pathologic findings, including histologic diagnoses on endometrial tissue samples. Results: Numeric chromosomal anomalies were found in 0% (0/50) of benign, 20% (10/50) of hyperplasia, 76% of atypical hyperplasia (38/50), and 86% (43/50) of carcinoma specimens. The mean percentage of cells with chromosomal changes was 54% in cancer specimens, significantly higher than that in hyperplasia without atypia (13%, p< 0.0001) and atypical hyperplasia (34%, p< 0.0001). The most frequent chromosomal anomaly was gain of chromosome 1. FISH anomalies had an overall sensitivity of 81% and specificity of 90% for the detection of atypical hyperplasia and/or endometrial carcinoma. There was no association with grade of endometrial carcinoma. Conclusions: Multi-target UteroFISH appeared to be useful for the differential diagnosis of reactive hyperplasia, atypical hyperplasia, and endometrial adenocarcinoma, with a high level of sensitivity and specificity. Endometrial hyperplasia with FISH-detected chromosomal anomalies may require close clinical follow-up. No significant financial relationships to disclose.
Detection of chromosomal anomalies in endometrial atypical hyperplasia and carcinoma by using fluorescence in situ hybridization