One case of pulmonary lymphoma of MALT origin is reported. The diagnos
is was made by histological and immunohistological study of surgical s
pecimen. Cytologically, the tumoral proliferation was made by an admix
ture of centrocyte-like cells, small lymphocytes and vacuolized plasma
cells. Lympho-epithelial lesions were particular because induced by t
umoral plasma cells. From this case, problems of diagnosis and physiop
athology of pulmonary MALT lymphomas are discussed.