Pleural tuberculosis: a key differential diagnosis for pleural thickening, even without obvious risk factors for tuberculosis in a low incidence setting.

We report the case of a 64-year-old woman, presenting with pleuritic chest pain and weight loss. She had a previous history of breast malignancy and no clear risk factors for tuberculosis (TB). Initial investigations showed a right-sided pleural effusion and pleural thickening suggestive of malignancy, which would have been in keeping with the clinical presentation. Initial pleural biopsy showed features suggestive of possible TB infection, though no growth on cultures. A repeat biopsy was negative on initial microscopy, but was culture positive for Mycobacterium tuberculosis, also identifying isoniazid resistance. This case highlights that TB remains an important differential even in the absence of classical risk factors, and illustrates the diagnostic challenges it poses. It also highlights the value of culture positivity in identification of drug resistance and facilitation of appropriate treatment.