IgD myeloma: a potential missed diagnosis.

This report describes a case of IgD lambda myeloma which was discovered only following investigation of a suspicious 'low gamma region'. If anti-IgD investigations had not been carried out, it may have been misinterpreted as Bence Jones myeloma. The case illustrates that evaluation of serum and urine in cases of suspected myeloma is mandatory and that the possibility of IgD myeloma in cases that appear to be 'free light chain' paraproteins only should be investigated.