Asbestos Fibres in Fine‐Needle Aspiration of a PET ‐Avid Pulmonary Nodule Reveal Mixed Pneumoconiosis in a Patient With Silicosis and Progressive Massive Fibrosis

Pneumoconiosis results from inhalation of occupational dusts and is most commonly due to silica, asbestos, or coal dust. Foundry workers are classically associated with silicosis; however, historical exposure to asbestos, particularly before regulatory restrictions in the 1980s, places this population at risk for mixed pneumoconiosis. Progressive massive fibrosis (PMF), an advanced form of pneumoconiosis, can radiographically and metabolically mimic malignancy, creating significant diagnostic challenges. Recognition of asbestos fibres in cytologic specimens is critical because of their prognostic, surveillance and medico-legal implications.