[1111] Diagnostic Clinical Application of Multi-Target Fluorescence In Situ Hybridization in Endometrial Biopsies: Prospective Study of 282 Cases

David G Bostwick, Delor Hossain, Elba Turbat-Herrera, Peter Schlosshauer. Bostwick Laboratories, Inc., Orlando, FL

Background: The diagnosis of endometrial hyperplasia, atypical hyperplasia, and well-differentiated endometrial adenocarcinoma is often challenging and prone to intra- and inter-observer variation. Genetic testing may allow more objective discrimination. We investigated the utility of chromosomal anomalies for the detection and diagnostic discrimination of endometrial abnormalities in biopsies using multi-target fluorescence in situ hybridization (FISH).
Design: Samples were prospectively collected by endometrial brush (Tao Brush®) or suction straw (Pipelle®) and processed by liquid-based cytological preparation protocol from 300 cases. A total of 18 cases were excluded owing to insufficient tissue (6%). Each of the remaining cases was hybridized using fluorescence-labeled DNA probes to chromosomes 1, 8, and 10. The FISH signals were enumerated in 100 cells per case, and the chromosomal anomalies were correlated with pathologic findings, including histologic diagnoses on matched endometrial tissue samples reviewed by at least two gynecologic pathologists. Given the small number (5) of cases of atypical hyperplasia, these were categorized as carcinoma for statistical analysis.
Results: Numeric chromosomal anomalies (positive FISH results) were found in 20% (6 of 30 cases) of benign endometrium, 27.8 % of hyperplasia without atypia (45 of 162), and 71.1 % (64 of 90) atypical hyperplasia/carcinoma specimens (P < 0.001)(WHO Classification). FISH anomalies had an overall sensitivity of 59.1% and specificity of 79.7% for the detection of atypical hyperplasia and/or endometrial carcinoma.
Conclusions: Multi-target FISH is useful for the differential diagnosis of hyperplasia, atypical hyperplasia, and endometrial adenocarcinoma, with moderate sensitivity and a high level of specificity. It is also a potential tool for the early detection of neoplastic cells in endometrial cytology specimens. Endometrial hyperplasia with FISH-detected chromosomal anomalies may represent a clinically significant subset of cases that warrants close clinical follow-up.
Category: Gynecologic & Obstetrics

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 130, Tuesday Morning


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