[Multifocal nodular AL amyloidosis in primary Sjögren's syndrome].

Primary Sjögren's syndrome (primary SS) is characterized by lymphocytic and plasma cell infiltration of the lacrimal and salivary glands, sometimes extending to extraglandular sites. An increased incidence of B-cell lymphoproliferative disorders has been observed in patients with primary SS. We recently studied an unusual case of primary SS associated with multifocal nodular AL amyloidosis (amyloidomas), located in the lower respiratory tract and oral mucosa. A 66-year-old woman with primary Sjögren's syndrome since 1966 was hospitalized in 1996 because of multifocal nodular shadows on a chest radiograph. An open lung biopsy specimen was obtained, revealing a large mass of amorphous eosinophilic material with green birefringence when stained with Congo red. Numerous plasma cells surrounded the amyloid deposits, aggregated in nodules and around blood vessels. The cytoplasm of these cells stained monotypically with anti-lambda light chain, using a peroxidase technique. Amyloid material did not stain with antibodies directed against kappa and lambda light chains, or against IgG, IgA and IgM heavy chains. Immunofixation of the serum and concentrated urine did not demonstrate monoclonal immunoglobulins. AL-amyloidomas might be a manifestation of local immunoglobulin production and amyloid formation within extramedullary plasmacytoma. This plasmacytoma might be burned out, namely, overcome by the deposits and no longer recognizable.