From the Research
The Infectious Diseases Society of America (IDSA) guidelines recommend obtaining a lung biopsy when less invasive diagnostic methods have failed to identify the cause of pulmonary infections, particularly in immunocompromised patients. Lung biopsies should be considered after non-diagnostic bronchoscopy with bronchoalveolar lavage, especially when patients have progressive disease despite empiric antimicrobial therapy 1. The guidelines specifically recommend lung biopsy for suspected invasive fungal infections, Pneumocystis pneumonia when sputum induction or bronchoscopy are negative, suspected malignancy, or unusual infections. The preferred approach is typically CT-guided transthoracic needle aspiration for peripheral lesions, while video-assisted thoracoscopic surgery (VATS) is recommended for deeper lesions or when larger tissue samples are needed 2. Open lung biopsy is reserved for cases where VATS is not feasible. Specimens should be sent for histopathology, cytology, and microbiological studies including cultures for bacteria, fungi, mycobacteria, and viruses. The timing of the biopsy is crucial, ideally performed before antimicrobial therapy is initiated or changed, but should not delay treatment in critically ill patients 3. These recommendations aim to balance the need for definitive diagnosis against the risks of an invasive procedure, and are supported by recent studies on the diagnosis and management of invasive fungal disease due to moulds other than Aspergillus in the haematology/oncology setting 4. Some key points to consider when deciding to perform a lung biopsy include:
- The patient's underlying condition and risk factors for pulmonary infections
- The results of less invasive diagnostic tests, such as bronchoscopy and imaging studies
- The potential benefits and risks of the biopsy procedure
- The need for a definitive diagnosis to guide treatment decisions.