When “TB” Worsens on Treatment

A 35-year-old woman, no comorbidities, has fever and cough since June 2025. She initially received antibiotics and cough suppressants without benefit. CT chest (Aug 2025) showed right lower lobe consolidation; BAL Xpert MTB positive (rifampicin indeterminate) and HREZ was started with good adherence.

By September 2025, symptoms persisted; repeat sputum Xpert remained positive (rif indeterminate), so moxifloxacin, amikacin, and steroids were added. Cough and weight loss continued into October, prompting PET-CT, which showed a hypermetabolic necrotic RLL lesion with active mediastinal nodes. EBUS tissue Xpert was negative, while BAL Xpert stayed positive and Rifampicin remain indeterminate and no growth in AFB Culture.

What is the most likely diagnosis?