Within the spectrum lymphoproliferative disorders that can affect the lung. Characterized by infiltration of the interstitium and alveolar spaces with lymphocytes, plasma cells, and lymphoreticular elements. Symptoms develop and progress slowly over the course of months and include cough, dyspnea, weight loss, fevers, and pleuritic chest pain. Physical examination reveals crackles. Additional physical findings relate to the underlying disease process.

Common disease associations include human immunodeficiency virus (HIV) infection in the pre-antiretroviral therapy (ART) era, Sjögren syndrome, hypergammaglobulinemia, common variable immunodeficiency, pernicious anemia, rheumatoid arthritis, and biliary cirrhosis.