Gastrointestinal pathologist consensus of revised high-grade dysplasia in inflammatory bowel disease impacts the...

The diagnosis of inflammatory bowel disease (IBD) associated with high-grade dysplasia (HGD) has a significant impact on clinical management, including colectomy. However, the prognosis of HGD remains unclear due to diagnostic uncertainty and low-quality data on subsequent synchronous and metachronous neoplasia. We aimed to evaluate a diagnostic strategy with dedicated gastrointestinal (GI) pathologist consensus of revised HGD and the impact on synchronous and metachronous neoplasia rates.

In this retrospective multicenter cohort study, we used the Dutch Nationwide Pathology Databank to identify IBD patients with HGD in seven hospitals. Histopathological specimens of the initial HGD were independently revised by two dedicated GI pathologists. Definitive diagnosis was established in a consensus meeting. Synchronous and metachronous neoplasia incidences were assessed with a competing risk analysis.

We included 54 IBD patients with HGD, of whom 33 (61.1%) with ulcerative colitis and 42 (77.8%) with extensive disease. After consensus, 18 (33.3%) lesions were downgraded to indefinite/low-grade dysplasia, and 6 (11.1%) were revised to colorectal cancer (CRC). Seven patients (13.0%) had synchronous CRC. Patients with downgraded lesions showed a lower cumulative advanced neoplasia (HGD/CRC) incidence compared with confirmed HGD [(Gray's test P < 0.01), 5-year cumulative incidence 0.0% vs. 26.6%].

We demonstrated frequent downgrading of HGD, associated with lower metachronous neoplasia rates. This underlines the potential impact of dedicated GI pathologist consensus meetings. The high and synchronous and metachronous neoplasia rates after HGD underline the need for close surveillance.