18F-FDG PET/CT Findings in Cytomegalovirus Colitis.

Anna Kjaer,Kim Thomsen,Per Ibsen,Jesper Graff,Iben Ribberholt,Elena Markova

doi:10.3390/diagnostics9010003

Abstract

We present a case demonstrating the diagnostic work-up of a patient undergoing azathioprine treatment for inflammatory bowel disease (IBD), diagnosed with an acute cytomegalovirus (CMV) infection and CMV colitis. An 18F-FDG positron emission tomography/computed tomography (PET/CT) performed 2 weeks after debut of symptoms revealed pathological 18F-FDG uptake in the left side of the colon mucosa, mimicked activity of IBD. However, a diagnosis of CMV colitis was based on the presence of CMV IgM antibodies, a seroconversion of CMV IgG antibodies, presence of CMV DNA in plasma and the finding af CMV DNA in biopsies from the intestinal mucosa. The patient responded to treatment with ganciclovir. This case highlights that a positive 18F-FDG PET/CT scan of the colon can be due to CMV colitis.

Highlights

CMV colitis as a complication in patients with inflammatory bowel disease (IBD) has been associated with active disease, immunosuppressive medication, steroid treatment, and especially steroid refractory disease progression [4]
Diagnosing CMV colitis is based on clinical symptoms, biochemical findings, typical endoscopic findings, histological examination of biopsies from colon mucosa, and detection of CMV DNA in the blood and biopsies from affected colon mucosa [1,2,3,4,5,6]
IBD patients with colitis and systemic signs of inflammation, steroid-refractory disease, pyrexia, splenomegaly, and a lack of leukocytosis have a high pre-test probability for CMV colitis [6] as was the case in our patient. 18F-FDG positron emission tomography/computed tomography (PET/CT) has been shown to have a potential for a noninvasive whole-body assessment of IBD, with FDG accumulating along the intestinal tract including assessment of disease extent, activity, and treatment response [7]