A 76-year-old male patient presented with fever, cough and dyspnoea for 4 days. His history included chemotherapy for chronic lymphoid leukaemia concluded 2 years before and use of ibrutinib and hyperimmune globulin for the last year. On chest X-ray, it was possible to identify complete atelectasis of the left upper lobe (LUL) (figure 1A, B). CT demonstrated a mass-like lesion causing obstruction of the respective lobar bronchus (figure 1C, D). The lesion showed intense focal abnormal uptake on fluorodeoxyglucose positron emission tomography/CT (figure 2A). There were no enlarged or hypermetabolic lymph nodes. Bronchoscopy demonstrated polypoid lesions occluding the LUL bronchus (figure 2B). Bronchoalveolar lavage was negative for neoplastic cells and obtained metaplastic and mature squamous epithelial cells with cytopathic changes, compatible with viral …