[Nodular amyloidoma associated with primary pulmonary Malt lymphoma]

Pulmonary amyloïdoma is a nodular formation containing amyloid deposits, which can mimick a pulmonary carcinoma. Its etiologic diagnosis require the search of an underlying infectious disease, a connective tissue disorder or a lymphoma.

We report the case of a 73 year old woman, asymptomatic, presenting an incidental pulmonary opacity in the left upper lobe, associated with hilar lymphadenopathies, positive on PET scan. The patient underwent a left superior lobectomy with mediastinal lymphadenectomy. Histologically, the nodule was composed of amylodosis deposits. It was surrounded by a dense lymphoïd infiltrate. The phenotype (CD20+, CD5-, CD3-, CD23-) of the lymphoïd cells, like the demonstration of a lambda light chain restriction permited to pose the diagnostic of pulmonary Malt lymphoma and to characterize the AL lambda type of the amyloïdosis

Association of amyloïdoma and Malt lymphoma is a rare condition. The histologic diagnosis of lymphoma may be difficult in this case, the lymphomatous process being concealed by the volume of the amyloïd mass. Therefore it is necessary in case of amyloïdoma to search histological signs of Malt lymphoma and to confirm diagnosis by demonstrating a B clonality and a immunoglobulin light chains restriction.