# Mycobacterial Infections Mimicking Malignancy in Solitary Pulmonary Lesions: A Cone Beam CT‐Guided Biopsy Case Series

## TL;DR

This case series shows that mycobacterial infections can mimic lung cancer and highlights the need for thorough testing to avoid unnecessary surgery.

## Contribution

The study emphasizes the importance of microbiological testing in diagnosing mycobacterial infections in solitary pulmonary nodules.

## Key findings

- Four out of five cases initially suspected as malignant were diagnosed with mycobacterial infections.
- A fifth case confirmed as mycobacterial after surgery had also tested positive in a retrospective biopsy review.
- Microbiological tests like PCR can help diagnose infections before histology results are available.

## Abstract

Solitary pulmonary lesions are often associated with malignancy. Cone beam computed tomography (CBCT) enhances bronchoscopic biopsy accuracy by confirming tool‐in‐lesion positioning. We present five cases of solitary pulmonary nodules initially suspected to be malignant based on imaging and clinical context. Despite clear tool‐in‐lesion confirmation via CBCT, initial pathology was non‐diagnostic for malignancy. Upon further microbiological analysis, four cases were diagnosed as mycobacterial infections. A fifth case, which underwent surgical resection due to persistent diagnostic uncertainty, was subsequently found to harbour mycobacterial infection; retrospective review of the original biopsy also confirmed this. These cases highlight the importance of including mycobacterial infections such as tuberculoma in the differential diagnosis of solitary pulmonary nodules and stress the need for comprehensive microbiological evaluation in CBCT‐confirmed biopsies, especially when histology is non‐malignant. Our findings also emphasise the potential diagnostic utility of microbiological tests—including PCR—even prior to histology review when CBCT confirms tool‐in‐lesion. This approach may prevent unnecessary surgical interventions and associated morbidity.

We present five cases of solitary pulmonary nodules initially suspected to be malignant based on imaging and clinical context. Despite clear tool‐in‐lesion confirmation via CBCT, initial pathology was non‐diagnostic for malignancy. Upon further microbiological analysis, four cases were diagnosed as mycobacterial infections. A fifth case, which underwent surgical resection due to persistent diagnostic uncertainty, was subsequently found to harbour mycobacterial infection; retrospective review of the original biopsy also confirmed this. These cases highlight the importance of including mycobacterial infections such as tuberculoma in the differential diagnosis of solitary pulmonary nodules and stress the need for comprehensive microbiological evaluation in CBCT‐confirmed biopsies, especially when histology is non‐malignant.