18F-FDG PET/CT in a case of multifocal skeletal tuberculosis without pulmonary disease and potential role for monitoring treatment response.

A 39-year-old man presented with left shoulder and interscapular pain. 99mTc-MDP bone scan demonstrated multiple active bone lesions including scapula, spines, ribs, and pelvis. Chest X-ray showed no active lung lesion, and MRI demonstrated infiltrative enhancing lesions in the T-spines and ribs, indicating skeletal metastasis. 18F-FDG PET/CT performed to search for hidden malignancy revealed multiple osteolytic lesions with intense FDG uptake, supporting metastasis. Tissue obtained from the T1 lesion showed no malignant cells but was positive for Mycobacterium tuberculosis. After 18 months of antituberculosis medication, follow-up 18F-FDG PET/CT showed complete normalization of FDG uptake in the skeletal lesions.