The connective tissue changes of Crohn's disease

Shelley-Fraser G, Borley N R, Warren B F & Shepherd N A ?(2012) Histopathology similar to 60, 10341044 The connective tissue changes of Crohns disease Although the inflammatory pathology of Crohns disease is manifestly its most important attribute, the connective tissue changes are important in the genesis of the more chronic features of the disease, and yet these have received little attention from clinicians, pathologists, and scientists. Fat-wrapping appears to be pathognomonic of Crohns disease, and is an important marker of disease for surgeons. There is evidence of a complex interplay between the effector inflammatory cells of Crohns disease and adipocytes, hyperplasia of which results in fat-wrapping. Pathologically, this is exhibited in the close relationship between the transmural inflammation that is so characteristic of Crohns disease and fat-wrapping. Fibrosis and muscularization are also important components of the chronic changes of intestinal Crohns disease. Neuronal and vascular changes make up the remaining connective tissue changes: these constitute a distinctive feature, and are even specific for Crohns disease. For pathologists, the combination of these connective changes will allow a diagnosis of chronic burnt-out Crohns disease, even in the absence of its highly characteristic inflammatory features. The connective tissue changes of Crohns disease form an important part of its long-term pathology. They deserve more attention from clinicians, diagnostic pathologists and researchers alike.