Spontaneous complete resolution of pneumomediastinum and pneumatosis intestinalis caused by acute GVHD
Authors: Fatma Keklik, Zuzan Cayci, Patrick Arndt, Celalettin Ustun
Journal: American Journal of Hematology (2016)

A 31-year-old male with relapsed Hodgkin lymphoma (nodular sclerosing) after autologous haemopoietic stem cell transplantation (HCT) received allogeneic (allo) HCT from an human leukocyte antigen (HLA) identical sibling donor for consolidation in second complete remission. He presented with acute diarrhea at day +34, and was diagnosed with gut grade II acute graft-versus-host disease (aGVHD) proven by histopathological examination of a rectal biopsy. Steroids initially controlled the diarrhea, however, gut aGVHD flared at day +100 while steroids were being tapered. This episode was severe and refractory to high dose steroids, requiring initiation of second line aGVHD treatment (i.e., antithymocyte globulin, etanercept). When his gastrointestinal tract (GIT) symptoms completely resolved, he had a routine chest computerized tomogrophy (CT) for follow-up of lung nodules at day +271. The chest CT demonstrated air tracking along the mediastinum (pneumomediastinum; curved arrows) (Image 1A) and free air in the upper abdomen (arrows; Image 1B). A subsequent abdominal CT done the same day showed extensive air tracking along the colonic walls consistent with severe pneumatosis intestinalis (PI) (arrows; Image 1C). He was asymptomatic (except for feeling bloated) and had no signs of acute abdomen. He has been monitored closely along with surgery team. At day +360 when he had no abdominal distention, a follow-up chest and abdominal CT demonstrated no evidence of pneumomediatenium or pneumointestinalis (Image 1D). CT images show air tracking in the anterior mediastinum, along the bowel wall and sub diaphragmatic region. Follow up CT images demonstrate complete resolution of the findings. PI characterized by the infiltration of air into the intestinal wall was rarely associated with severe, acute gut GVHD as observed in our patient 1. Few case reports/series have also reported that PI is associated with chronic GVHD 1, 2. Several mechanisms have been proposed and discussed in pathogenesis of PI 3. One theory suggests “air leak” originates from the GIT due to immunosuppressive therapy or GVHD leading to some atrophy of gastrointestinal lymphoid tissue (Peyer patches) with severe-diffuse mucosal disruption leading to bowel wall dissection by intraluminal gas (the immunosuppression theory). Coexisting infections (e.g., Clostridium and Escherichia species), severe inflammatory infiltration, and steroid use can also contribute to GVHD associated PI. The pulmonary theory, in contrast, suggests that alveolar rupture results in dissection of air along pulmonary interstitium to the mediastinum and then retroperitoneally through vessels to the abdominal viscera. Some patients, in particular, those with chronic GVHD can be asymptomatic 1, 3. Clinical course varies: most PI patients without a sign of surgical acute abdomen will improve with aggressive supportive therapy, including bowel rest and antibiotics (in addition to GVHD therapy). However, this can be a life-threatening complication leading to bacterial peritonitis or severe sepsis in approximately 20% of all patients with PI regardless of its etiology 4, 5. A higher mean APACHE II score, older age, and sepsis are associated with a higher mortality rate in patients with PI 4, 5. Surgical treatment—it was used more commonly in the past decades—can be associated with high mortality and morbidity 4, 6. CT scan findings can be useful to differ severe, clinically worrisome cases from benign PI (e.g., mesenteric stranding, bowel wall thickening, and ascites, and diffuse PI) 7. FK literature search, writing, and editing the manuscript (medicine resident); ZC providing the images, writing, and editing the manuscript (radiologists); PA diagnosis of the patient, writing, and editing the manuscript (pulmonologist); CU conceiving the idea, management of the patient, literature search, writing, and editing the manuscript (hematologist).