Proper tissue orientation is a critical part of the histologic evaluation of biopsies of the gastrointestinal tract. Tissue orientation is a two-step process that involves the coordinated actions of the endoscopist and the histotechnologist. The endoscopist should mount the biopsy mucosal side up on an appropriate solid surface (e.g., filter paper) and place it in fixative. This first step should be done immediately, in the endoscopy suite, so that the specimen does not dry out en route to the surgical pathology laboratory. The histotechnologist can then embed and cut the biopsy specimen perpendicular to the mounting surface. If the specimen is free floating, great care must be taken to identify the mucosal surface for proper embedding. Multiple sections should be cut from each tissue block for histologic evaluation. Step sections are preferred to serial sections so that intervening unstained sections are available for special stains as needed.
KeywordsInflammatory Bowel Disease Large Intestine Focal Lesion Ileocecal Valve Distal Resection Margin
Unable to display preview. Download preview PDF.