Discrepancies in histologic diagnoses of early gastric cancer between biopsy and endoscopic mucosal resection specimens

A preoperative histologic diagnosis of neoplasia is a requirement for endoscopic resection (ER). However, discrepancies may occur between histologic diagnoses based on biopsy specimens versus ER specimens. The aim of this study was to assess the rate of discrepancy between histologic diagnoses from biopsy specimens and ER specimens. A total of 1705 gastric lesions, from 1419 patients with a biopsy diagnosis of neoplasia, were treated by ER from September 2002 to December 2008. We compared the histologic diagnosis from the biopsy sample and the final diagnosis from the ER specimen to assess the discrepancy rate. Clinicopathological characteristics of the lesions that were related to the histologic discrepancies were also studied. An ER diagnosis of gastric cancer was made in 49% (118/241) of lesions diagnosed as borderline lesions from biopsy specimens; this included adenomas and lesions difficult to diagnose as regenerative or neoplastic. The size, existence of a depressed area, and ulceration findings were significant factors observed in these lesions. An ER diagnosis of differentiated type cancer was obtained for 17% (12/63) of lesions diagnosed as undifferentiated type cancer from the biopsy specimens; for these lesions, the color and a mixed histology were significant factors related to the histologic discrepancies. A biopsy diagnosis of borderline lesions or undifferentiated type cancer is more likely to disagree with the diagnosis from ER specimens. Endoscopic characteristics should be considered together with the biopsy diagnosis to determine the treatment strategy for these lesions.