Primary pulmonary lymphoma

A rare neoplastic disease defined as a clonal lymphoid proliferation affecting one or both lungs (parenchyma and/or bronchi) in a patient with no detectable extrapulmonary involvement at diagnosis or during the subsequent 3 months. PPL comprises low grade/indolent B cell PPL forms, the most frequent form represented by the marginal B-cell lymphoma of mucosa associated lymphoid tissue (MALT lymphoma) and other non-MALT low grade lymphomas; and more rarely high-grade B-cell PPL (including diffuse large B cell lymphoma) and lymphomatoid granulomatosis (LYG).