Myeloma, FISH, Fixed Cells
Aiding in the diagnosis of new cases of multiple myeloma
Identifying prognostic markers based on the anomalies found
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Multiple myeloma is a hematologic neoplasm that generally originates in the bone marrow and develops from malignant plasma cells. There are 4 main categories of myeloma: asymptomatic myeloma, smoldering myeloma, indolent myeloma, and multiple myeloma. Asymptomatic myeloma patients have nonspecific symptoms that may be attributed to other diseases. Generalized bone pain, anemia, numbness or limb weakness, symptoms of hypercalcemia, and recurrent infections are all symptoms that may indicate myeloma. In smoldering myeloma there is a monoclonal protein spike, but it is stable. Indolent myeloma is a slowly progressing myeloma.
As myeloma progresses, the malignant plasma cells interfere with normal blood product formation in the bone marrow resulting in anemia and leukopenia. Myeloma also causes an overstimulation of osteoclasts, causing excessive breakdown of bone tissue without the normal corresponding bone formation. These bone lesions are seen in approximately 66% of myeloma patients. In advanced disease, bone loss may reach a degree where the patient suffers fractures easily.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not approved by the FDA and is best used as an adjunct to existing clinical and pathologic information.
The establishment of normal cutoffs on fixed cell pellets was determined based on analysis of 25 normal bone marrow specimens. Validation of the probes was performed on 81 specimens referred with an indication of myeloma using the cytoplasmic immunoglobulin (cIg) FISH method. Of these 81 specimens, 45 had sufficient plasma cells for analysis (at least 25 plasma cells per hybridization site). Of 45 specimens, 44 (98%) specimens were found to be abnormal for the probe sets used.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Fonseca R, Blood E, Rue M, et al: Clinical and biologic implications of recurrent genomic aberrations in myeloma. Blood 2003 Jun 1;101(11):4569-4575
2. Fonseca R, Blood EA, Oken MM, et al: Myeloma and the t(11;14) (q13;q32); evidence for a biologically defined unique subset of patients. Blood 2002 May 15;99(10):3735-3741
3. Shaughnessy J, Tian E, Sawyer J, et al: High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH. Blood 2000 Aug 15;96(4):1505-1511