Lesions indefinite for intraepithelial neoplasia and OLGA staging for gastric atrophy.

Gastric intraepithelial neoplasia (IEN; formerly dysplasia) is an advanced precancerous lesion. Lesions indefinite for IEN mimic the IEN phenotype but lack some morphologic attributes of IEN. Indefinite for IEN lesions may arise in native foveolae (atypical foveolar hyperproliferation [aFH]) or intestinalized glands (hyperproliferative intestinal metaplasia [HIM]). The clinicopathologic outcome of such lesions is debated. We retrospectively studied the clinicopathologic behavior of 129 consecutive indefinite for IEN lesions (HIM, 98; aFH, 31; median follow-up, 31 months) and correlated outcome with the extent and topography of mucosal atrophy (assessed by OLGA staging) at the initial endoscopy/biopsy. At enrollment, aFH never coexisted with severe/extensive atrophy (all cases were in low-risk OLGA stages [0-II]), whereas HIM was associated with low- and high-risk OLGA stages (0-II, 73; III-IV, 25). At follow-up, IEN was never documented among cases enrolled as aFH, while follow-up endoscopy/biopsy documented 6 neoplastic intraepithelial lesions among 98 cases of HIM (6%, all had high-risk OLGA stages at initial biopsy). OLGA staging can stratify indefinite for IEN lesions into different risk classes, potentially contributing to decisions for a patient-specific follow-up strategy.