hematology and oncology
Heavy Chain Diseases
IgM Heavy Chain Disease (mu chain disease)
IgM heavy chain disease, which is rare, produces a clinical picture similar to chronic lymphocytic leukemia or other lymphoproliferative disorders. 50 years. Visceral organ involvement (spleen, liver, abdominal lymph nodes) is common, but extensive peripheral lymphadenopathy is not. Pathologic fractures and Amyloidosis may occur. Serum protein electrophoresis usually is normal or shows hypogammaglobulinemia. Bence Jones proteinuria (typeκ) is present in 10 to 15% of patients. CBC may show anemia, leukopenia, thrombocytopenia, eosinophilia, and circulating atypical lymphocytes or plasma cells. Diagnosis usually requires bone marrow examination; vacuolated plasma cells are present in two thirds of patients and, when present, are virtually pathognomonic. Death can occur in a few months or in many years. The usual cause of death is uncontrollable proliferation of Chronic Lymphocytic Leukemia (CLL) cells. Treatment depends on the patient’s condition but may consist of alkylating agents plus corticosteroids or may be similar to treatment of the lymphoproliferative disorder that it most closely resembles. 