Mixed dust pneumoconiosis occurring in an unusual setting

Abstract

Mixed dust pneumoconiosis secondary to domestic wood smoke exposure is a cause of pneumoconiosis in women from developing countries, but is rarely seen in the USA. An elderly female non-smoker, who immigrated to the USA from Pakistan 10 years previously, presented with a worsening non-productive cough and dyspnoea on exertion. She did not have any occupational or environmental exposures other than utilising firewood for cooking while living in Pakistan. Radiographs revealed multiple bilateral pulmonary nodules associated with hilar and mediastinal adenopathy. A video-assisted thoracoscopic biopsy revealed ill-defined nodules in a perivascular subpleural deposition, carbon pigment deposition around the terminal bronchioles, dust macules and negatively birefringent needles on polarised light microscopy with mixed dust nodules outnumbering the silicotic nodules consistent with mixed dust pneumoconiosis. This case illustrates the need for awareness of this condition among physicians caring for women who lived in areas where biomass exposure is common.