Nonconventional dysplasia in patients with inflammatory bowel disease and colorectal carcinoma: a multicenter clinicopathologic study

Non‐conventional dysplasias of the tubular gut: a review and illustration of their histomorphological spectrum

“…More recently, Choi et al . reported that hypermucinous dysplasia was the most common non‐conventional subtype (42%) identified in a cohort of 58 IBD patients with colorectal cancer 91 …”

“…Serrated dysplasia in IBD shows a typical saw‐toothed or stellate architecture 93,94 . This category includes sessile serrated lesion (SSL)‐like and TSA‐like dysplasias, as well as serrated dysplasia not otherwise specified 91,95 . Serrated dysplasia commonly coexists with conventional dysplasia or other subtypes of non‐conventional dysplasia as a minor or predominant component 91 .…”

“…In colectomy specimens, the reported prevalence of serrated dysplasia in the neighbouring mucosa of IBD‐associated carcinomas ranges from 12% to 29% 93,94 . A recent multicentre clinicopathological study reported that TSA‐like dysplasia was the most common serrated subtype (28% of non‐conventional dysplasia cases), followed by serrated dysplasia not otherwise specified (11%) and SSL‐like dysplasia (3%) 91 …”

“…The IBD‐associated serrated dysplasias have similar clinicopathological features as their respective sporadic counterparts (Figure 10B). 91,96–100 However, among seven gastrointestinal pathologists, the overall interobserver agreement rate for SSL‐like and serrated dysplasia not otherwise specified in IBD patients was reported to be intermediate (≥60% agreement), whereas the agreement rate for TSA‐like dysplasia was the lowest (<50% agreement) 91,95 . In a recent study that evaluated a variety of immunohistochemical and molecular markers, 7% of serrated dysplasias were the only dysplastic lesions positive for BRAF 101 .…”

Non-conventional dysplastic subtypes in inflammatory bowel disease: a review of their diagnostic characteristics and potential clinical implications

“…Although pathologists have a good grasp of the morphologic criteria of conventional dysplasia, several unfamiliar morphologic patterns of dysplasia (collectively known as "non-conventional" dysplasia) have been recently described in IBD. There are at least seven subtypes, including (1) hypermucinous dysplasia; (2) crypt cell dysplasia; (3) dysplasia with increased Paneth cell differentiation; (4) goblet cell deficient dysplasia; (5) SSL-like dysplasia; (6) TSA-like dysplasia; and (7) serrated dysplasia NOS [38,[41][42][43]. Although their clinicopathologic and molecular features are not fully characterized, in part due to the rarity of these subtypes and the likelihood that they are under-recognized, the recognition of these non-conventional subtypes is becoming increasingly important, as they often present as invisible/flat lesions, and at least some of them appear to have a higher malignant potential than conventional dysplasia or sporadic adenomas.…”