Bowel inflammatory presentations on computed tomography in adult patients with severe aplastic anemia during flared inflammatory episodes

BACKGROUND: Patients with severe aplastic anemia (SAA) frequently present with inflammatory episodes, and during flared inflammatory episodes, hematopoietic function is further exacerbated. The gastrointestinal tract is the most common site for infectious and inflammatory diseases, and its structural and functional features confer on it the most potent capacity to affect hematopoietic and immune functions. Computed tomography (CT) is a readily accessible approach to provide highly useful information in detecting morphological changes and guiding further work-ups. AIM: To explore CT imaging presentations of gut inflammatory damage in adult SAA patients during inflammatory episodes. METHODS: We retrospectively evaluated the abdominal CT imaging presentations of 17 hospitalized adult patients with SAA in search of the inflammatory niche when they presented with systemic inflammatory stress and exacerbated hematopoietic function. In this descriptive manuscript, the characteristic images that suggested the presence of gastrointestinal inflammatory damage and related imaging presentations of individual patients were enumerated, analyzed and described. RESULTS: All eligible patients with SAA had CT imaging abnormalities that suggested the presence of an impaired intestinal barrier and increased epithelial permeability. The inflammatory damages were concurrently present in the small intestine, the ileocecal region and the large intestines. Some readily identified imaging signs, such as bowel wall thickening with mural stratification (“water holo sign”, “fat holo sign”, intramural gas and subserosal pneumatosis) and mesenteric fat proliferation (fat stranding and “creeping fat sign”), fibrotic bowel wall thickening, “balloon sign”, rugged colonic configuration, heterogeneity in the bowel wall texture, and adhered and clustered small bowel loop (including various patterns of “abdominal cocoon”), occurred at a high incidence, which suggested that the damaged gastrointestinal tract is a common inflammatory niche responsible for the systemic inflammatory stresses and the exacerbated hematopoietic failure in patients with SAA. Particularly, the “fat holo sign” was present in 7 patients, a rugged colonic configuration was present in 10 patients, the adhesive bowel loop was present in 15 patients, and extraintestinal manifestations suggestive of tuberculosis infections were present in 5 patients. According to the imaging features, a suggestive diagnosis of Crohn’s disease was made in 5 patients, ulcerative colitis in 1 patient, chronic periappendiceal abscess in 1 patient, and tuberculosis infection in 5 patients. Other patients were diagnosed with chronic enteroclolitis with acutely aggravated inflammatory damage. CONCLUSION: Patients with SAA had CT imaging patterns that suggested the presence of active chronic inflammatory conditions and aggravated inflammatory damage during flared inflammatory episodes.