Franklin’s disease: immunoglobulin heavy chain disease

A 64-year-old male presented with persistent fatigue, weakness and abdominal discomfort. He was found to have pancytopenia and hepatosplenomegaly. His bone marrow examination was mildly hypocellular with trilineage hematopoiesis. Serum protein electrophoresis revealed broad beta protein area but no gamma monoclonal spike (A). Surprisingly, immunofixation study identified monoclonal γ-heavy chain with no corresponding κ- or λ-light chains (B).