Rheumatic fever: a forgotten but still existing cause of fever of unknown origin detected on FDG PET/CT.

We present a case of heterogeneous and strongly increased myocardial and valvular 18F-FDG uptake on 18F-FDG PET/CT in an HIV-positive patient with productive cough, fever, weight loss, and progressive dyspnea for 6 months. Contrast-enhanced CT did not reveal the cause of fever, but hyperechogenic valvular lesions on echocardiography in combination with PET/CT findings are suggestive of endocarditis/myocarditis. Postmortem histology 3 weeks after PET/CT showed Aschoff bodies with Anitschkow cells, pathognomonic for rheumatic carditis. This case illustrates that rheumatic heart disease can be detected on 18F-FDG PET/CT and demonstrates the value of 18F-FDG PET/CT in patients with fever of unknown origin.