Predictable factors of histologic discrepancy of gastric cancer between the endoscopic forceps biopsy and endoscopic treatment specimen.

BACKGROUND/AIMS: Recently, variable gastrointestinal track tumors including early stage malignancies are treated by endoscopic procedure. However, the discrepancy of histologic diagnosis may sometimes exist between the pretreatment forceps biopsy results and those of post treatment specimen. So the prediction of malignant lesion is important in the aspect of treatment selection. In this study, we investigated the predictable factors of the histologic discrepancy through the clinical, endoscopic features of the lesion diagnosed as adenocarcinoma in the post-endoscopic treatment specimen after the adenoma was diagnosed by the endoscopic forceps biopsy.
METHODS: From March 2005 to April 2009, 129 gastric tumor lesions (129 patients) which were not diagnosed as malignancy and treated with endoscopic procedure were enrolled retrospectively. We compared the pretreatment endoscopic forceps biopsy results and post-treatment specimen biopsy results, then, analyzed the tumor characteristics.
RESULTS: Twenty-one cases (16.3%) were diagnosed as malignancy after endoscopic treatment. Especially, discrepancy occurred more frequently in depressed lesions than in flat or elevated lesions (41.7% vs. 13.7%, p=0.012), and in lesions diagnosed as high grade adenomas than low or moderate grade adenomas (33.3% vs. 11.1%. p=0.004).
CONCLUSIONS: In cases of depressed type lesions in the pretreatment endoscopy or those diagnosed as high grade adenoma in the pretreatment forceps biopsy, we should consider combined malignant lesion. Therefore, treatment modalities ensuring accurate diagnosis and potentially curative resection, should be carefully selected and performed in cases which have these features.