Clinical Presentation and Management of Pulmonary Infection Caused by Mycobacterium paraffinicum

Non-tuberculous mycobacteria (NTM) are environmental organisms that rarely cause infections in healthy individuals but can be opportunistic pathogens in those with compromised immune systems or chronic lung conditions. <i>Mycobacterium paraffinicum</i>, a newly recognized species, is among these rare pathogens. We report a rare case of pulmonary infection with <i>M. paraffinicum</i>, detailing its clinical presentation, investigative findings, and treatment outcome. A 50-year-old male smoker with a history of chronic obstructive pulmonary disease (COPD), severe emphysema, and other comorbidities presented with chronic cough, progressive shortness of breath, and weight loss. Initial clinical suspicion focused on pulmonary tuberculosis (TB) due to his symptoms and family history, but sputum smear microscopy and subsequent biopsy revealed <i>M. paraffinicum</i>. This diagnosis was confirmed by culture showing sensitivity to clarithromycin and amikacin and intermediate sensitivity to moxifloxacin. Investigations included chest X-ray and high-resolution computed tomography (HRCT), which revealed a large left apical cavity, progressive nodular wall thickening, and bilateral inflammatory nodules. The patient was initially managed as TB, but virology and serology screens were negative for common pathogens, including TB. The pivotal biopsy identified the NTM infection, leading to a revised diagnosis. Treatment was managed by a multidisciplinary team and included a regimen of rifampicin, ethambutol, azithromycin, and intravenous amikacin, alongside chest physiotherapy. Over a 12-month period, the patient showed significant clinical improvement, with reduced cough, improved appetite, and weight gain. Follow-up radiographs demonstrated notable improvement in the lung cavity. This case underscores the importance of considering NTM infections in differential diagnoses of cavitating lung lesions, particularly when initial treatments for TB are unsuccessful. Despite the lack of established treatment guidelines for <i>M. paraffinicum</i>, a combination of targeted antibiotics and supportive care proved effective. This case contributes to the limited literature on <i>M. paraffinicum</i>, highlighting the need for awareness and further research on management strategies for this rare pathogen.