Abstract

Extranodal involvement of NHL is detected in 25-40% of patients, while primary lung involvement is very rare. Primary pulmonary lymphoma (PPL) is defined as clonal lymphoid proliferation involving one or both lungs in a patient with no detectable extrapulmonary involvement at diagnosis, or following 3 months. Bronchus associated lymphoid tissue (BALT) lymphoma comprises more than two-thirds of all primary pulmonary lymphomas. PPL generally follow an indolent and slow clinical course and is detected incidentally on radiograms. It may masquerade as pneumonia and lung tumors, and this disease should be kept in mind, especially in the differential diagnosis of nonresolving pneumonias.