CHRONIC MUCOSAL CHANGES OF THE COLON IN GRAFT-VERSUS-HOST DISEASE

The histologic features of acute graft-versus-host disease (GVHD) of t he colon are well documented, but chronic mucosal changes associated w ith GVHD are poorly described, We report here the clinicopathologic fi ndings from five patients with a history of bone marrow transplantatio n in which colonoscopic biopsies showed chronic mucosal changes remini scent of chronic idiopathic inflammatory bowel disease (IBD). The pati ents ranged in age from 2.5 to 31 years. Bone marrow transplantations were performed for leukemia (3 patients), Hodgkin's disease (1 patient ), and metachromatic leukodystrophy (1 patient). Endoscopy was perform ed because of complaints of abdominal pain and diarrhea in all of the five patients. The mean time after transplantation in which histologic features of chronicity were identified was 5.8 months (range, 3-16 mo ). All of the five patients had prior colonic biopsies showing acute G VHD, One patient had a previous episode of cytomegalovirus infection. Chronicity was characterized by mild-to-moderate architectural distort ion, i.e.,, villiform surface with crypt branching and atrophy, simila r to that seen in chronic idiopathic IBD. The lamina propria was hypoc ellular, with prominent small blood vessels. Focal fibrosis of the lam ina propria was noted. One patient had active cryptitis, Superimposed changes of acute GVHD were mild to absent. None of the patients had a history of IBD before receiving the bone marrow transplant. Changes as sociated with chronicity can be observed in mucosal biopsy specimens f rom patients with GVHD, It is uncertain whether these changes are dire ctly caused by GVHD or are the result of superimposed infections. The association of chronic mucosal change in the setting of GVHD with the clinical diagnosis of chronic GVHD needs additional investigation.