Pseudolymphoma of the lung in a patient with systemic lupus erythematosus

A 47 year old woman with systemic lupus erythematosus was found to have asymptomatic pulmonary nodules. Histologically they represented benign reactive lymphoreticular hyperplasia compatible with the diagnosis of pseudolymphoma. Immunofluorescence and electron microscopy demonstrated immunoreactants and electron-dense deposits in the alveolar and vascular walls, suggesting that an immune complex mechanism may be involved in this case.