Paraneoplastic acute fibrinous and organizing pneumonia from lymphoma completely responding to bendamustine-rituximab

Acute fibrinous and organizing pneumonia (AFOP) is a rare histopathological pattern of lung injury characterized by prominent fibrin deposition in alveolar spaces. It may be idiopathic or associated with medications, connective tissue disease, infection, environmental exposures, transplantation, and malignancy. There is no proven treatment but multiple reports describe response to corticosteroids. We report the case of a 65-year-old male never-smoker with a 15-month history of dry cough, dyspnoea, anorexia, and night sweats only partially responsive to doxycycline and oral prednisolone. Computed tomography chest demonstrated adenopathy on both sides of the diaphragm and patchy consolidation in a peribronchovascular and subpleural distribution with lower zone predominance. Axillary node biopsy revealed low-grade non-Hodgkin's lymphoma. Lung biopsy showed AFOP but no lymphoma. Complete pulmonary and neoplastic responses were achieved with bendamustine-rituximab. We report a compelling instance of paraneoplastic AFOP responding to chemotherapy for lymphoma with very limited use of corticosteroids.