Triclonal gammopathy in an extranodal non-Hodgkin lymphoma patient.

The case of a patient with an extranodal non-Hodgkin lymphoma and three M-components (IgGkappa + IgGlambda + IgMlambda) in the serum is described. Three separate populations of M-component producing cells have been identified. Since a kappa-->lambda chain switch is not demonstrated, the synthesis of IgGkappa and IgGlambda by two distinct clones is obvious. IgMlambda and IgGlambda M-components are synthesized by two different plasma cell populations that could represent two unrelated cell clones or, alternatively, two subclones originated by a common precursor. After chemotherapy the IgGlambda M-component is replaced by heavy gamma chains without evidence of lambda light chains. Copyright 2003 Wiley-Liss, Inc.