Endoscopic and histological staging of lower gastrointestinal graft-versus-host disease (GI-GVHD)

Upper panel: Endoscopic views of the colon with the four grades of GI-GvHD. Grade 1 = loss of vascular markings and/or focal mild erythema; grade 2 = moderate edema and/or erythema; grade 3 = edema, erythema, erosions, and/or bleeding; grade 4 = ulceration, exudates, and bleeding.
Lower panel: Photomicrograph of the colon corresponding to the above endoscopic images: grade 1 = increased crypt apoptosis (arrows); grade 2 = apoptosis with crypt abscess (arrow); grade 3 = individual crypt necrosis (arrow); grade 4 = total denudation of areas of mucosa (H & E; x220).