Abstract
Bronchiolitis obliterans organizing pneumonia (BOOP) presents with fever, dyspnoea, pleuritic chest pain and hypoxia. The diagnosis can be made from radiological appearances on chest radiograph and CT scan correlated with histological findings following biopsy. We present a 52-year-old gentleman undergoing treatment for high grade non-Hodgkin's lymphoma who developed respiratory symptoms during chemotherapy. BOOP was diagnosed and he responded well to oral prednisolone. The cause of BOOP is often not certain. However, in this case we suspect pegylated filgrastim or rituximab as possible agents.