Most lymphoid proliferations in the lung are either localized or manifestations of leukemias/secondary lymphomas that are not forms of interstitial lung disease. However, follicular bronchiolitis (FB), multinodular lymphoid hyperplasia (MNLH), and diffuse expansile lymphoid infiltrates (DELI, also called lymphoid interstitial pneumonia-LIP) do represent ILD when diffuse (when localized they are nonspecific reactions). These three entities are strongly associated with connective tissue disease, particularly Sjogren syndrome, and with immunodeficiency states such as common variable immunodeficiency and selective IgA deficiency.