18th February 2025

A 40-year-old lady is admitted with haemoptysis, weight loss and fevers for one month.

A 40-year-old lady is admitted with haemoptysis, weight loss and fevers for one month. She has a contact history with a family member who has recently been diagnosed with active TB. A chest X-ray shows upper lobe infiltrates with cavitation. 

Investigations are as follows:

Sputum Ziehl Neelsen stain: Negative

Tuberculin skin test: Inconclusive

What is the most appropriate investigation to confirm diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.