Lymphocytic interstitial pneumonitis is a benign lymphoproliferative disorder of the lung that is characterized by the presence of a dense, predominantly lymphocytic interstitial infiltrate (lymphocytes, plasma cells, other elements of the lymphoreticular system) that expands the alveolar septa. [https://orcid.org/0000-0002-0736-9199, pmid:32040879]

Lymphocytic interstitial pneumonia (LIP) is a syndrome secondary to autoimmune and other lymphoproliferative disorders. Symptoms include fever, cough, and shortness of breath...