**Solitary plasmacytoma with minimal marrow involvement**

Biopsy-proven solitary lesion of bone or soft tissue with evidence of clonal plasma cells.

Clonal bone marrow plasma cells <10%.

Normal skeletal survey and MRI (or CT) of spine and pelvis (except for the primary solitary lesion) Absence of end-organ damage such as hypercalcemia, renal insufficiency, anemia, or bone lesions that can be attributed to a lymphoplasma cell proliferative disorder.

**Heavy-chain disease** is a rare monoclonal gammopathy characterized by synthesis and secretion of free heavy-chain fragments and is seen associated with diseases including lymphoplasmacytic lymphoma and an unusual small bowel marginal zone lymphoma that occurs in malnourished populations (so-called Mediterranean lymphoma).

**Smoldering multiple myeloma**—both criteria must be met.


**Multiple myeloma** is a plasma cell neoplasm commonly associated increased plasma cells in the marrow with accompanying features like lytic bone lesions, hypercalcemia, renal failure, and acquired immune abnormalities. It is commonly seen in older adults, with a peak age of incidence of 65–70 years.

Revised International Myeloma Working Group diagnostic criteria for multiple myeloma and smoldering multiple myeloma [68].

Definition of multiple myeloma

• Clonal bone marrow plasma cells ≥10% or biopsy-proven bony or extramedullary plasmacytoma\* and any one or more of the following myeloma defining events:

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**Figure 9.**

*B-Cell Lymphomas*

*DOI: http://dx.doi.org/10.5772/intechopen.87370*

cell proliferative disorder, specifically:

upper limit of normal or >2.75 mmol/L (>11 mg/dL)

• Renal insufficiency: creatinine clearance 177 μmol/L (>2 mg/dL)

• Evidence of end-organ damage that can be attributed to the underlying plasma

• Hypercalcaemia: serum calcium >0.25 mmol/L (>1 mg/dL) higher than the

• Anemia: hemoglobin value of >20 g/L below the lower limit of normal, or a

• Bone lesions: one or more osteolytic lesions on skeletal radiography, CT, or

Multiple myeloma is characterized by infiltration of marrow by plasma cells in the interstitium, nodules or in diffuse sheets that completely replace normal elements (**Figure 9**). Plasma cells can be relatively normal-appearing plasma cells, plasmablasts or binucleated and multinucleated cells. Other cytologic

positron emission tomography-computed tomography (PET-CT)

Anyone or more of the following biomarkers of malignancy

• Clonal bone marrow plasma cell percentage\* ≥60%

• Involved: uninvolved serum free light chain ratio§ ≥100

*Bone marrow biopsy showing sheets of plasma cells replacing normal hematopoietic elements.*

Myeloma defining events:

hemoglobin value <100 g/l

• 1 focal lesion on MRI studies

*6.10.1 Morphology and immunophenotype.*

Myeloma defining events:

*Normal and Malignant B-Cell*

**Solitary plasmacytoma**

plasma cells.

plasma cells.

proliferative disorder.

Mediterranean lymphoma).

**Light-chain monoclonal gammopathy of undetermined significance**

Increased level of the appropriate involved light chain (increased κ FLC in

The absence of end-organ damage such as hypercalcemia, renal insufficiency, anemia, and bone lesions (CRAB) or amyloidosis that can be attributed to the plasma cell proliferative disorder Clonal bone marrow plasma cells<10%.

Biopsy-proven solitary lesion of bone or soft tissue with evidence of clonal

Normal skeletal survey and *magnetic resonance imaging* (MRI) or Computed tomography (CT) of spine and pelvis (except for the primary solitary lesion) Absence of end-organ damage such as hypercalcaemia, renal insufficiency, anemia, or bone lesions (CRAB) that can be attributed to a lymphoplasma cell proliferative disorder.

Biopsy-proven solitary lesion of bone or soft tissue with evidence of clonal

Normal skeletal survey and MRI (or CT) of spine and pelvis (except for the primary solitary lesion) Absence of end-organ damage such as hypercalcemia, renal insufficiency, anemia, or bone lesions that can be attributed to a lymphoplasma cell

**Heavy-chain disease** is a rare monoclonal gammopathy characterized by synthesis and secretion of free heavy-chain fragments and is seen associated with diseases including lymphoplasmacytic lymphoma and an unusual small bowel marginal zone lymphoma that occurs in malnourished populations (so-called

• Serum monoclonal protein (IgG or IgA) ≥30 g/L or urinary monoclonal protein ≥500 mg per 24 h and/or clonal bone marrow plasma cells 10–60%.

**Multiple myeloma** is a plasma cell neoplasm commonly associated increased plasma cells in the marrow with accompanying features like lytic bone lesions, hypercalcemia, renal failure, and acquired immune abnormalities. It is commonly

Revised International Myeloma Working Group diagnostic criteria for multiple

• Clonal bone marrow plasma cells ≥10% or biopsy-proven bony or extramedullary plasmacytoma\* and any one or more of the following myeloma defining

patients with a ratio >1.65 and increased λ FLC in patients with a ratio). No immunoglobulin heavy chain expression on immunofixation.

Normal bone marrow with no evidence of clonal plasma cells.

**Solitary plasmacytoma with minimal marrow involvement**

**Smoldering multiple myeloma**—both criteria must be met.

• Absence of myeloma defining events or amyloidosis.

seen in older adults, with a peak age of incidence of 65–70 years.

myeloma and smoldering multiple myeloma [68].

Definition of multiple myeloma

Abnormal free light chain (FLC) ratio (<0.26 or >1.65).

Urinary monoclonal protein <500 mg/24 h.

Clonal bone marrow plasma cells <10%.

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events:


Anyone or more of the following biomarkers of malignancy

