Acute fibrinous and organizing pneumonia in systemic lupus erythematosus: a case report and review of the literature.

Pulmonary manifestations of systemic lupus erythematosus (SLE) typically include pleuritis, alveolar hemorrhage, and infectious pneumonia due to immunosuppression with less common entities including bronchiolitis, interstitial pneumonia, and pulmonary fibrosis. More rare manifestations include organizing pneumonia (OP) and diffuse alveolar damage (DAD). A similar but distinct entity of acute fibrinous and organizing pneumonia (AFOP), characterized by intra-alveolar fibrin deposition and associated organizing pneumonia, has been reported in association with connective tissue disorders, but has not been described in association with SLE. Reported herein is a patient with SLE and accompanying antiphospholipid syndrome with recent pulmonary embolism, persistent respiratory symptomology, and persistent radiographic abnormalities who underwent lung biopsy displaying features of AFOP. This case in conjunction with previous literature indicates that AFOP can be a manifestation of connective tissue disease including SLE and may be an underreported variant of medical lung disease due to overlap in histological characteristics with OP and DAD.