Pulmonary Tuberculosis Masking Lung Adenocarcinoma: A Diagnostic Pitfall Following Apparent Treatment Response.

Pulmonary tuberculosis and lung cancer may present with overlapping clinical and radiological features, making diagnosis challenging. We report the case of a 42-year-old chronic smoker with bacteriologically confirmed pulmonary tuberculosis who showed marked clinical and radiological improvement after anti-tuberculosis therapy. Within 20 days of this apparent favorable evolution, the patient developed hemoptysis associated with rapid clinical deterioration. Imaging revealed a right hilar mass with metastatic disease. Bronchoscopic findings and histopathological examination confirmed lung adenocarcinoma (TTF-1 positive). This case highlights how apparent treatment response can be misleading and may delay the recognition of an underlying malignancy. Reassessment should be considered when the clinical course becomes atypical or rapidly progressive, particularly in high-risk patients.