Abstract
A 62-year-old Japanese female with Sjögren's syndrome (SS) was admitted to our hospital because of fever, weight loss and parotid swelling. She has been diagnosed of having pseudolymphoma 1 year prior to the admission because of pulmonary lesion. Biopsy specimen obtaind from the parotid gland, lymph node and lung tissue demonstrated no apparent invasion of malignant cells but severe infiltration of lymphoid cells. Formation of myoepithelial islands was also observed. Analysis of immunoglobulin gene rearrangement by Southern blotting revealed a rearranged band in the parotid gland DNA. Furthermore, polymerase chain reaction (PCR) amplification clearly showed an appearance and expansion of monoclonal B cell population in the biopsy specimen from the lymph node and the lung. However, parotid swelling spontaneously regressed and pulmonary lesions almost disappeared without any treatment. We here discussed the importance of immunoglobulin gene analysis in the course of SS and the significance of monoclonal B cell expansion in SS.
