This is a 36-years old man with fever of unknown origin. A chest radiograph showed mediastinal widening. A CT scan of the chest showed left para-aortic nodes. Prior to a biopsy, a PET/CT was done, which along with the mediastinal nodes, showed a focal area of soft tissue thickening with uptake in the left 8th intercostal space.

 

This was unexpected and had been missed on the earlier CT scan. This is also easier to biopsy than the left para-aortic mediastinal nodes. I used an 18G coaxial biopsy gun for this extra-pleural lesion. 6 cc of pus was aspirated. The final diagnosis was tuberculosis, culture positive, but PCR negative.

This is an unusual site for tuberculosis. But with TB, there is no point getting surprised on where it can land up and what it can mimic.