Multiple myeloma is a type of cancer formed by mclassant B-lymphocytes, their clonal proliferation and accumulation of terminal stages-plasmocytes (myeloma cells). These myeloma cells form monoclonal immunoglobulin and other cytokines that result in various symptomps of different intensity. Multiple myeloma is frequently associated with osteolysis, renal dysfunctions and anemia. Multiple myeloma is a clinical entity that corresponds, according to WHO (2001), to a morphological entity called plasma cell myeloma, see table 1.
Table 1: Clinical terms of mclassant monoclonal gammopathy and the corresponding histologic entities according to the WHO classification
| Clinical syndrome, clinical entity | Histologic entity according to WHO classification (2001) |
| Multiple myeloma | Plasma cell myeloma |
| Immunoglobulin deposition disease Primary AL-amyloidosis Light chain deposition disease |
Plasma cell myeloma |
| Polyneuropathy, Organomegaly, Endocrine abnormalities, Monoclonal gammopathy, Skin changes |
Osteosclerotic myeloma, Multicentric Castleman´s disease |
| Waldenström's macroglobulinemia | Lymphoplasmocytic lymphoma |
| Heavy chain disease Gamma haevy chain disease Alfa heavy chain disease |
Lymphoplasmocytic lymphoma Chronic lymphocytic leukemia Mucosa-associated lymphoid tissue (MALT) |
