Background: Primary Sjögren's syndrome (pSs) is an autoimmune rheumatic disease that may express in a small number of patients a spectrum of lymphoproliferative diseases. The aim of this study was to describe clinical, imaging and pathology features of the extranodal marginal zone B-cell lymphoma (MZCL) of the lung of mucosa-associated lymphoid tissue (MALT) type in patients with pSs.
Methods: All patients (N=10) with biopsy proven MZCL of the lung of MALT type diagnosed in a tertiary teaching hospital during the last 7 years were studied.
Results: Seven patients had pSs. Almost all patients presented an indolent clinical course, contrasting strongly with the spectacular radiological findings in both chest roentgenograms and computed tomography. Pathology infiltration patterns observed were either nodular, peribronchial-perivascular, alveolar, or interstitial. Immunohistochemical study in all cases showed B cell phenotypes. Immunoglobulin light chain restriction was demonstrated in all patients. Monoclonal IgM(kappa) was evident in 5/7, IgM(lambda) in 1/7 and IgG (kappa) in 1/7 of patients.
Conclusions: Lung MZCL associated with pSs are characterized by an important dissociation between clinical expression and radiological pattern. Clinical presentation and imaging features are not specific. Therefore, histologic documentation is mandatory to ensure diagnosis. Various chemotherapeutic agents in combination with rituximab lead to partial or complete remission in the majority of patients.