The natural history of monoclonal villous lymphocytosis: a chronic lymphoproliferative disorder of CD11c+ B cells.

The long-term outcome of three asymptomatic subjects with isolated persistent lymphocytosis of monoclonal villous B-cells (MVL) is reviewed. After 7.5 years, evolution to a splenic lymphoma variant (SLVL) was documented in only one patient, accompanied by a loss of interleukin-1beta autocrine production, confirming that MVL can be an early form of a malignant disorder. The clinical course was uneventful in the other two cases; a progressive lowering of lymphocyte count being noted in one. While the strict relationship of MVL to SLVL is confirmed, time to progression is unpredictable and the mechanisms by which it occurs still remain to be elucidated.