Coexistence of systemic lupus erythematosus (SLE) with low-grade non-Hodgki
n's lymphoma (LGNHL) has been described occasionally in the literature with
the potential pathogenetic role of monoclonal B CD5+/CD19+ cells. We repor
t a case of LGNHL which developed 18 months after diagnosis of SLE. The mon
oclonal population of lymphocytes ia the peripheral blood and bone marrow w
as CD5/CD19 negative but CD19/CD22 positive. The SLE responded well to trea
tment with prednisone and the course of the LGNHL was stable and cytotoxic
treatment was not required.