Intestinal and Extraintestinal Findings of Graft-versus-Host Disease on CT: A Case Series with Radiological and Histopathological Correlations.

Graft-versus-host disease (GVHD) is an expected and relatively common complication after allogeneic hematopoietic stem cell transplantation. It may affect different organs and typically involves the skin, liver, and gastrointestinal tract (GI-GVHD). GI-GVHD may show heterogeneous presentations with peculiar diagnostic implications. Although an endoscopic biopsy is considered the "gold standard" for the diagnosis of GI-GVHD, its broad application is limited due to the poor clinical conditions usually present in these patients, including thrombocytopenia. In the emergency department, enhanced computed tomography (CECT) has emerged as the best imaging modality for the evaluation of GI damage in frail patients. However, the role of CT in the context of either acute or chronic GI-GVHD has not been systematically investigated. Herein, we focus on the radiological features found on CECT in five patients with GI-GVHD confirmed on histology. CECT was performed for the persistence of GI symptoms in three cases (case 1, case 3, and case 4), for small bowel occlusion in one case (case 5), and for acute GI symptoms in one case (case 2). Serpiginous intestinal wall appearance with multisegmental parietal thickness and homogeneous, mucosal, or stratified small bowel enhancement were common features. Colic involvement with segmental or diffuse parietal thickness was also present. One patient (case 5) presented with inflammatory jejunal multisegmental stenosis with sub-occlusion as a chronic presentation of GI-GVHD. Regarding mesenterial findings, all five patients presented comb signs in the absence of lymphadenopathy. Extraintestinal findings included biliary tract dilatation in two cases (case 2 and case 4). These data support the utility of appropriate radiological investigation in GI-GVHD, paving the way for further serial and systematic investigations to track the appearance and evolution of GI damage in GVHD patients.