EBV-positive diffuse large B-cell lymphoma in a patient with primary Sjögren’s syndrome and membranous glomerulonephritis

BACKGROUND Sjögren's syndrome is a systemic autoimmune disease in which lymphatic cells destroy the salivary and lacrimal glands. Glomerulonephritis is thought to be a rare occurrence in primary Sjögren's syndrome. Furthermore, concurrent glomerular involvement and lymphoma in patients with Sjögren's syndrome has seldom been reported. CASE PRESENTATION A 52-year-old woman with primary Sjögren's syndrome developed membranous glomerulonephritis and Epstein-Barr virus-positive diffuse large B-cell lymphoma (DLBCL). She was diagnosed with Sjögren's syndrome based on the dry eyes, dry mouth, positive anti-nuclear antibody test, anti-Ro (SS-A) antibody, salivary gland biopsy, and salivary scintigraphy. Moreover, renal biopsy confirmed the diagnosis of membranous glomerulonephritis. Three months later, her small bowel was perforated with pneumoperitoneum, and the biopsy revealed Epstein-Barr virus-positive DLBCL. CONCLUSIONS We observed the first case of primary Sjögren's syndrome associated with Epstein-Barr Virus-positive DLBCL and membranous glomerulonephritis. Because of the possibility of malignancy-associated membranous glomerulonephritis in patients with primary Sjögren's syndrome, we should be careful and examine such patients for hidden malignancy.