18F-FDG PET and PET/CT in diagnosis and treatment monitoring of pyrexia of unknown origin due to tuberculosis with prominent hepatosplenic involvement.

The potential of (18)F-FDG PET/CT in the diagnosis and treatment response monitoring of fever of unknown origin (resulting from hepatosplenic tuberculosis) is demonstrated in this report. The patient was a 32-y-old woman who had presented to us with a history of pyrexia of unknown origin for the past 2 mo. On investigation, she was found to have hepatic and splenic granulomas, with whole-body (18)F-FDG PET demonstrating abnormal (18)F-FDG-avid foci in the liver and spleen. Ultrasonography-guided liver biopsy was suggestive of granulomatous hepatitis. The patient was clinically nonresponsive to first-line antitubercular drugs, and second-line antitubercular medications were added subsequently in view of clinical nonresponse. The patient responded well to the treatment. The repeated CT scan at 11 mo demonstrated persistence of the splenic granulomas; however, follow-up (18)F-FDG PET/CT at the same time showed resolution of (18)F-FDG-concentrating active disease foci with suggestion of complete metabolic response, commensurate with the patient's clinical improvement.