Summary of characteristics of EMM
| Characteristics . | Summary of features . |
|---|---|
| Definition | Soft-tissue plasmacytoma or PC infiltration of an anatomical site distant from the bone marrow (eg, strict extramedullary disease as defined in Table 1) |
| Incidence | 6% to 8% in de novo patients 10% to 30% in relapsed/refractory patients |
| Molecular pathogenesis | CD44high, CD56low, CXCR4/CXCL12 Hypoxia Ras, P53, FAK mutations |
| Clinical characteristics | Symptoms related to organ involvement Mostly liver, skin, CNS, pleural effusion, kidneys, lymph nodes, pancreas |
| Biological characteristics | High LDH, anemia, thrombocytopenia High-risk gene expression profile High-risk cytogenetics (17p deletion) |
| Morphology | Frequent immature/plasmablastic morphology |
| Staging | Value of PET-CT to detect extramedullary disease CNS EMM: MRI, CSF analysis (morphology, flow cytometry, protein electrophoresis) |
| Prognosis | EMM is an independent adverse prognostic factor in de novo MM patients receiving intensive therapy. Few series specifically analyzed the particular outcome of EMM. |
| Characteristics . | Summary of features . |
|---|---|
| Definition | Soft-tissue plasmacytoma or PC infiltration of an anatomical site distant from the bone marrow (eg, strict extramedullary disease as defined in Table 1) |
| Incidence | 6% to 8% in de novo patients 10% to 30% in relapsed/refractory patients |
| Molecular pathogenesis | CD44high, CD56low, CXCR4/CXCL12 Hypoxia Ras, P53, FAK mutations |
| Clinical characteristics | Symptoms related to organ involvement Mostly liver, skin, CNS, pleural effusion, kidneys, lymph nodes, pancreas |
| Biological characteristics | High LDH, anemia, thrombocytopenia High-risk gene expression profile High-risk cytogenetics (17p deletion) |
| Morphology | Frequent immature/plasmablastic morphology |
| Staging | Value of PET-CT to detect extramedullary disease CNS EMM: MRI, CSF analysis (morphology, flow cytometry, protein electrophoresis) |
| Prognosis | EMM is an independent adverse prognostic factor in de novo MM patients receiving intensive therapy. Few series specifically analyzed the particular outcome of EMM. |
CSF, cerebrospinal fluid; CXCL, CXC chemokine ligand; CXCR, CXC chemokine receptor; FAK, focal adhesion kinase; LDH, lactate dehydrogenase; MRI, magnetic resonance imaging; PET-CT, positron emission tomography/computed tomography.