Diffuse lymphadenopathy as the presenting manifestation of systemic lupus erythematosus.

We report the case of a 27-year-old African American man who presented with 6 months of generalized lymphadenopathy and nothing in his history or examination to suggest systemic lupus erythematosus (SLE). He was thought to have lymphoma, syphilis, or tuberculosis, and an extensive workup was done. Laboratory investigation finally revealed leukopenia (4.0), proteinuria (1.87 g), antinuclear antibodies (640 speckled), anti-double-stranded DNA (640), anticardiolipin immunoglobulins G and M, anti-Smith, Coombs, anti-Ro, anti-La, CK (531 U/L), aldolase (8.5 U/L), high erythrocyte sedimentation rate (130 mm/h), and low complement (C3 15 mg/dL and C4 3 mg/dL). A kidney biopsy showed diffuse proliferative glomerulonephritis, International Society of Nephrology class IV. Generalized lymphadenopathy as the first and only manifestation for 6 months made the diagnosis of SLE challenging. Generalized diffuse lymphadenopathy has been associated with SLE but is much less frequent now than in the past. The differential diagnosis of lymphadenopathy relevant to rheumatologists includes Kikuchi histiocytic necrotizing lymphadenitis, Castleman disease, syphilis, tuberculosis, sarcoidosis, and lymphoma.