Dust to Disease: Cavitary Lung Lesion With <i>Mycobacterium kansasii</i> in a Black Lung Patient

<i>Mycobacterium kansasii</i> is a slow-growing mycobacterium commonly affecting the lungs, usually in a structurally deformed lung. We discuss a case of 67-year-old male with a medical history of complicated coal workers pneumoconiosis or coal mine dust lung disease presented to the pulmonary clinic with worsening dyspnea and hemoptysis with imaging findings revealing cavitary lung lesions in the right upper lobe and progressive massive fibrosis (PMF) bilaterally. Patient sputum gram stain showed acid-fast bacilli, and the cultures grew <i>M. kansasii</i>. He was started on rifampin, ethambutol, and azithromycin. This case highlights the importance of thorough workup of cavitary lung lesion, reinforcing the association of mycobacterium species in a patient with PMF and associated cavities.