[Mucosa-associated lymphoid tissue lymphoma with Sjögren's syndrome].

A 68-year-old woman presented with Sjögren's syndrome. Chest X-ray films disclosed consolidated shadows in the right S2 and an infiltration shadow in the right S8 with small nodules. Pathological examination of transbronchial lung biopsy (TBLB) specimens revealed lymphocytic infiltrations that stained positive with UCHL-1 and L 26 in immunohistochemical studies. Lung tissue specimens obtained by video-assisted thoracic surgery showed lympho-epithelial lesions with dense lymphocytic infiltration. Southern blot hybridization and polymerase chain reaction (PCR) assays demonstrated monoclonality and immunoglobulin heavy chain gene rearrangement. These findings yielded a diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma. The detection of rear-ranged genes encoding for immunoglobulin heavy chains is useful for the diagnosis of primary pulmonary lymphoproliferative disorders, especially malignant lymphomas.