We report two cases of villous adenoma of the duodenum, one arising from the main papilla and the other from the accessory papilla. Both were managed by local resection. In one case endoscopic biopsies and intraoperative frozen sections were negative for carcinoma but histology of the locally resected specimen revealed a focus of invasive adenocarcinoma. Villous adenomas of the duodenum have a high risk of malignant change and foci of carcinoma can be missed on endoscopic biopsy. The literature is reviewed and the clinical, diagnostic, pathological and therapeutic aspects of villous adenomas of the duodenum are discussed.

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A commercial colorimetric indophenol (IP) method is used for determining monochloramine (NH2Cl) concentrations for process control in chloraminated public water systems and chloramine–related research. The NH2Cl – IP method excludes some quality control procedures typically included in drinking water methods and is not approved by the United States Environmental Protection Agency (U.S. EPA) for compliance monitoring. Therefore, the authors developed and validated a more complete NH2Cl–IP method, building on the commercial technique, as a candidate for future approval. During method development, temperature impact on color development was investigated. Color development time increased as temperature decreased. Below 20 °C, times needed for full color development were greater than those reported in the commercial method, reaching nearly three times longer at 5 °C. This observed temperature dependence also applies to free ammonia and free chlorine indophenol methods. To avoid measurement errors of samples analyzed below 20 °C, use of reaction times determined in this study is recommended for these indophenol methods.