Diagnosis, risk stratification, and management of ampullary dysplasia by DNA flow cytometric analysis of paraffin-embedded tissue

The limited accuracy of endoscopic biopsy in detecting high-grade dysplasia or adenocarcinoma within ampullary adenoma or dysplasia has been reported. The natural history of ampullary dysplasia is also unclear, and there are no established guidelines to determine which patients with ampullary dysplasia require resection versus surveillance endoscopy. DNA flow cytometry was performed on 47 ampullary biopsies with low-grade dysplasia, 18 high-grade dysplasia, and 23 negative for dysplasia, as well as 11 cases of ampullary adenocarcinoma. Abnormal DNA content (aneuploidy or elevated 4N fraction > 6%) was identified in 9 (82%) of adenocarcinoma, 13 (72%) of high-grade dysplasia, 7 (15%) of low-grade dysplasia, and none (0%) of non-dysplastic mucosa. One-, 2-, and 7-year detection rates of high-grade dysplasia or adenocarcinoma in low-grade dysplasia patients with abnormal DNA content were 57%, 86%, and 88%, respectively, whereas low-grade dysplasia patients in the setting of normal DNA content had 1-, 2-, and 7-year detection rates of 10%, 10%, and 10%, respectively. The univariate and multivariate hazard ratios (HRs) for subsequent detection of high-grade dysplasia or adenocarcinoma in low-grade dysplasia patients with DNA content abnormality were 16.8 ( p =