Miliary EGFR mutated non‐small cell lung cancer

A 58‐year‐old man presented with shortness of breath on exertion and cough. The patient was previously very fit with excellent exercise tolerance. He had a light, distant smoking history and travelled to Japan, Hong Kong and the United Kingdom within the past 12 months. Physical examination was unremarkable. Computed tomography imaging (Figure, A and B) demonstrated innumerable miliary nodules throughout both lungs and two larger nodules in the right apex, initially raising the suspicion of tuberculosis. Biopsy confirmed lung adenocarcinoma. Next generation sequencing detected a mutation in exon 19 of the epidermal growth factor receptor (EGFR) gene. The patient commenced gefitinib, an oral tyrosine kinase inhibitor. Other differential diagnoses to consider with this imaging appearance include histoplasmosis, blastomycosis, coccidioidomycosis, sarcoidosis, pneumoconioses and viral pneumonias.