[Hypermucinous and goblet cell-deficient, IBD-associated, non-conventional dysplasia besides colorectal adenocarcinoma].

Patients with inflammatory bowel disease (IBD) are twice as likely to develop colorectal carcinoma as the general population. In addition to invasive malignancy, these patients are also more likely to develop dysplasia, as well. In recent years, several subtypes of the so-called IBD-associated, non-conventional dysplasias have been identified, and the amount of information about these laesions show an increasing tendency, due to the many ongoing investigations. We present the case of a 62-year-old woman, diagnosed and treated with relapsing ulcerative colitis for 14 years. In the patient’s subtotal colectomy specimen, alongside ulcerative colitis, invasive adenocarcinoma with mucinous areas of the sigmoid colon was identified. In the immediate vicinity of the tumor, we observed goblet cell-deficient and hypermucinous, IBD-associated, non-conventional dysplasia, the latter with distinct intestinal and foveolar subtypes. IBD-associated, non-conventional dysplasias certainly require increased attention in both diagnostics and clinical routine, as these laesions may be flat, and difficult to detect by the examiner during endoscopy. The recognition of these lesions is of great importance for the pathologist, as their differentiation from reactive and reparative processes is often challenging. They are more often associated with high-grade dysplasia and colorectal carcinoma, and may also be possible precursors of invasive carcinoma. Regarding their molecular background, they are more often associated with aneuploidy. All these factors indicate a higher prognostic risk compared to conventional neoplasms, and, given their potentially difficult endoscopic appearance, closer follow-up and possible random biopsy sampling of IBD patients is recommended. Orv Hetil. 2023; 164(51): 2039–2044.