Sputum smear and Gene-Xpert negative pulmonary tuberculosis; a diagnostic dilemma in primary tuberculosis

Abstract

We discuss a case of a 60-year-old man with no known comorbidities who presented with sudden onset severe haemoptysis and chest pain. Sputum and pleural fluid smears for acid fast bacillus and Gene-Xpert were repeatedly negative. Pleural fluid cytology demonstrated presence of fungal organisms with hyphae and serum IgE was elevated. The patient developed a haemorrhagic pericardial effusion and cardiac tamponade. Sputum mycobacterial culture after 7 weeks was positive for Mycobacterium tuberculosi. This case highlights the difficulties that may be associated with diagnosis of PTB in the acute clinical setting and the importance of mycobacterial culture, particularly in the presence of negative initial investigations and superadded non-tuberculous infections. Furthermore, it demonstrates the potential clinical course of MTB infection, including development of severe extra-pulmonary complications. Finally, it highlights the importance of the multidisciplinary team in assessing the need to presumptively start anti-TB medication in selected cases.

Keywords

• mycobacterium tuberculosis
• pulmonary tuberculosis
• extra-pulmonary tuberculosis
• mycobacterial culture