Pulmonary MALT Lymphoma in Patients with Sjögren's Syndrome

To describe clinical features and outcomes of seven patients with pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma in the setting of underlying primary Sjögren's syndrome from a single center, we reviewed medical records of consecutive patients with pulmonary MALT lymphoma evaluated at our facility from January 1, 1999 to December 31, 2015 for clinical features, laboratory, pathologic and radiographic findings, management, and outcomes. Out of 13 patients with pulmonary MALT lymphoma, 7 (54 %) met the criteria for Sjögren's syndrome. The mean age at lymphoma diagnosis was 66 years; male-female ratio was 1:6. One-third of patients were asymptomatic at the time lymphoma was discovered. When symptomatic, patients reported nonspecific pulmonary complaints such as cough and dyspnea. All patients had positive antinuclear antibody and anti-SSA/Ro antibody. Rheumatoid factor was positive in six cases. A monoclonal gammopathy was present in three patients; the remaining four had polyclonal hypergammaglobulinemia. The radiologic, morphologic, and immunohistochemical features of primary Sjögren's syndrome-associated pulmonary MALT lymphomas did not differ significantly from pulmonary MALT lymphoma cases in general. All treatment modalities used resulted in complete and sustained response. One patient died 11 years after initial diagnosis with no lymphoma but of another cause. The remaining six patients are still alive and disease-free to date. The present series confirms the favorable course of pulmonary MALT lymphoma in Sjögren's patients. The overall imaging and pathologic features are in accordance with pulmonary MALT lymphoma not associated with primary Sjögren's syndrome. Further studies should be carried out in order to better understand pulmonary MALT lymphomagenesis, treatment, and outcomes in Sjögren's patients.