Pathologic stage at diagnosis: 1 pTa (1 MC); 14 pTis (6 UC, 1 AC, 5 SC,. 2 CN); 22 pT1 (6 UC, 3 AC, ...... Medicine, Nagoya, Aichi, Japan. Background: The RET ...
ANNUAL MEETING ABSTRACTS because they were over age 80 and as such, the IHC results were likely due to acquired methylation of the MLH1 promoter. The remaining 4 patients with absent staining have been referred to Cancer Genetics for possible further work-up. The reimbursement rate and turn-around time for the IHC stains were similar to that for other IHC stains used in clinical practice. Conclusions: IHC stains for the MMR proteins are fast and relatively easy to institute in routine evaluation of CRC, and we have not had difficulty interpreting the stains leading to additional testing. Furthermore, reimbursement was obtained at a level similar to other IHC stains used in clinical practice. The surgeons and oncologists welcomed the prognostic information. Further study is warranted to confirm these initial findings. 597 High Fidelity Image Cytometry in Neoplastic Lesions in Barrett’s Esophagus, Including Basal Crypt Dysplasia-Like Atypia with Surface Maturation X Zhang, Q Huang, R Goyal, RD Odze. VA Boston Health Care System, Boston, MA; Brigham and Women’s Hospital, Boston, MA. Background: Chromosomal instability and DNA aneuploidy is a key event in the progression of cancer in Barrett’s esophagus (BE). Automated image cytometry using high fidelity DNA histograms have been shown to be more sensitive and less susceptible to technical and interpretation issues than flow cytometry for analyzing cellular DNA content. Basal crypt dysplasia-like atypia (BCDA), with surface maturation, has recently been reported to represent an early form of true dysplasia in BE. The aim of this study was to evaluate DNA content in the progression of neoplasia in BE including cases of BCDA, with surface maturation. Design: Eighty-two formalin fixed mucosal biopsies from 65 BE patients (M/F ratio: 6.3, mean age: 65 yrs.), representing the full range of neoplasia [negative (n = 2), indefinite (n = 2), BCDA (n = 14), low grade dysplasia (LGD, n = 17), high grade dysplasia (HGD, n = 19), and adenocarcinoma (AD, n = 28)] were stained with H and E and Feulgen and evaluated for DNA content using an automated cellular imaging system (ACIS) to generate high fidelity DNA histograms. Histograms consisted of DNA index (DI), representing integrated optical density relative to stromal cells in the same section and were classified into diploid (peak DI = 0.9 – 1.1), mild aneuploidy (peak DI = 1.1 – 1.3), moderate aneuploidy (peak DI = 1.3 – 1.8), and severe aneuploidy (peak DI >1.8). Results: The prevalence of aneuploidy increased significantly (p
