There are several types of plasma cell neoplasms. All of these diseases are related to a protein (protein M) monoclonal (or myeloma). They include the monoclonal gammopathy of undetermined significance (GMSI), solitary plasmacytoma of bone, extramedullary plasmacytoma and multiple myeloma.
| Plasma cell neoplasm | M protein type | pathology | Clinical presentation | |
| GMSI | κ or λ, or κ or λ IgA IgG | < 10% of plasma cells in the bone marrow | Asymptomatic, with minimum test of disease (as well as the presence of a protein M) | |
| Solitary bone plasmacytoma | κ or λ, or κ or γ IgA IgG | solitary bone lesion; < 10% of plasma cells in the bone marrow of an unencumbered site | Asymptomatic or symptomatic | |
| Extramedullary plasmacytoma | κ or λ, or κ or γ IgA IgG | solitary lesion of tissue soft; occurs most frequently in the nasopharynx, tonsils or sinuses | Asymptomatic or symptomatic | |
| Multiple myeloma | κ or λ, or κ or γ IgA IgG | often, multiple bone lesions | Symptomatic | |
GMSI = gammopathy monoclonal of undetermined significance.
Evaluation of patients with protein (protein M) monoclonal (or myeloma)
The idiotype of the myeloma cells found in the blood of patients with myeloma in all stages of the disease. For this reason, and when treatment is indicated, a systemic treatment for all patients with symptomatic plasma cell Neoplasms should be considered.
GMSI or latent, asymptomatic myeloma patients do not need immediate treatment but it should be carefully monitored for signs of progression of the disease.
The most important challenge lies in separating a group of stable asymptomatic patients who do not need treatment of patients with symptomatic myeloma that evolves, that should be treated immediately.
Patients with a protein (protein M) monoclonal (or myeloma) in serum or urine must be evaluated with some of the following criteria:
• Measurement and monitoring of the M protein serum serum electrophoresis or specific trials of immunoglobulin; However, the specific quantification of immunoglobulin always overestimates the M protein because the result includes normal immunoglobulins. For this reason, the point of comparison and monitoring of protein measurements M should be made with the same method.If an M protein is not evident, the quantification of serum free light chains can be useful to track the response.
• Measurement and monitoring of the amount of light chains of M protein excreted in the urine for 24 hours. The total amount of protein excreted over 24 hours is measured and this value is multiplied by the percentage of M-protein in urine according to what determines concentrated urine protein electrophoresis. An easier, but less accurate, method is the method used an electrophoresis of protein spots in a urine sample.
• Identification of the strings heavy and light protein M by immunofixation electrophoresis.
• Measurement of hemoglobin, leukocytes, platelets and differential counts.
• Sometimes, determination of the percentage of plasma cells in the bone marrow. To note that the distribution of plasma cells in the bone marrow can vary at different sites.
• Measurement of the light chains κ and λ in the serum-free. This is especially useful in cases of dyscrasia oligosecretoras plasma cells or to keep track of cases of light chain Amyloidosis.
• Aspirates extramedullary a solitary lytic bone lesion, tumor (s) needle (s) or node (s) lymphatic (s) enlarged (s to determine if they are plasmacytomas).
• Evaluation of renal function serum creatinine and a creatinine clearance.
• Concentrated urine protein electrophoresis is very useful because unlike tubular lesions Glomerular lesions. Lesions Glomerular, as deposits that give resulting Glomerular amyloid or light chain disease, dan resulting non-selective loss of serum proteins in the urine; This urine electrophoresis configuration resembles serum configuration with a predominance of albumin.
In the majority of myeloma patients, the glomeruli normally feature that they leak urine only small molecular weight proteins, as the light chains. The concentration of proteins in the tubules increases as the water is reabsorbed.
This leads to the precipitation of proteins and the formation of tubular cylinders, which may damage the tubular cells. Tubular lesions, characteristic of the electrophoresis configuration shows a small albumin peak and a peak larger than a light chain in the globulin region; This tubular configuration is usually found in myeloma patients.
• Measurement of serum concentrations of calcium, alkaline phosphatase, LDH, and, when indicated by the clinical symptoms, cryoglobulins and serum viscosity.
• X-rays of the skull, ribs, vertebrae, pelvis, waist, shoulder girdle and long bones. It is in assessment the use of computed tomography of low dose with multiple detectors without contrast and images by magnetic resonance imaging (MRI) of the entire body as measures to monitor response to treatment. The MRI of the spine or the long bones are more sensitive for detecting lytic lesions, but still determine the prognosis or therapeutic for this information.
• Independent medical review if you detect a paraspinal mass or if symptoms indicate compression of the spinal cord or nerve roots.
• If suspected amyloidosis, do a needle aspiration of abdominal subcutaneous fat and stain the bone marrow biopsy to detect substances amyloid as the way to more easily and securely confirm the diagnosis.
• Measurement of serum albumin and the β-2-microglobulin as independent prognostic factors.
• High (≥3%) plasma cell labeling index or the presence of myeloma in circulation cells are precarious prognostic factors considered.Primary plasma cell leukemia has a particularly poor prognosis.