The value of serum free light chains in a case of Waldenstrom's macroglobulinaemia that produces a type I cryoglobulinaemia.

Lymphoplasmacytic lymphoma (Waldenstrom's macroglobulinaemia) is a low-grade small-cell lymphoma that produces monoclonal IgM. Usually, clinical features are related to growth of the tumour and include weakness and fatigue, an increased bleeding tendency, and neurological and visual disturbances. We present a case of lymphoplasmacytic lymphoma with type I cryoglobulinaemia that presented with clinical symptoms associated with hyperviscosity syndrome. Quantitation of the paraprotein was not possible using conventional serum protein electrophoresis due to the high serum viscosity, and therefore monitoring was carried out using serial serum free light chain measurements.