Multiple Myeloma how to diagnose
Multiple myeloma is a type of blood cancer that originates in the plasma cells within the bone marrow. These abnormal cells multiply uncontrollably, producing defective antibodies that can cause various health issues. Diagnosing multiple myeloma early is crucial for initiating effective treatment and improving patient outcomes. The diagnostic process involves a combination of clinical evaluation, laboratory tests, imaging studies, and sometimes, biopsy procedures.
Initially, healthcare providers assess symptoms and medical history. Patients may present with symptoms such as bone pain, fatigue, recurrent infections, anemia, elevated calcium levels, or kidney dysfunction. While these symptoms are not exclusive to multiple myeloma, their presence warrants further investigation.
Laboratory tests are fundamental in diagnosing multiple myeloma. A primary blood test is the serum protein electrophoresis (SPEP), which detects abnormal monoclonal proteins (also called M-proteins or paraproteins) produced by malignant plasma cells. Elevated levels of these proteins are characteristic of the disease. A complementary test, the urine protein electrophoresis (UPEP), looks for Bence Jones proteins—light chains excreted in the urine that are often associated with multiple myeloma.
Blood counts are also examined to identify anemia, common in these patients due to marrow infiltration. Additionally, serum free light chain assays measure the amount of free light chains in the blood, aiding in detection and monitoring of the disease. Elevated calcium levels, renal function tests (such as serum creatinine), and markers of bone turnover provide further insights into disease severity and organ involvement.
Imaging studies play a vital role in identifying bone lesions characteristic of multiple myeloma. Skeletal surveys, which include X-rays of the skull, spine, pelvis, ribs, and long bones, may reveal lytic lesions—areas of bone loss caused by tumor infiltration. However, these can sometimes be missed or appear late. More sensitive imaging modalities like Magnetic Resonance Imaging (MRI) or Positron Emission Tomography (PET) scans provide detailed visualization of bone marrow involvement and detect subtle lesions or extramedullary disease.
A definitive diagnosis often requires a bone marrow biopsy. This procedure involves extracting a sample of marrow from the hip bone or another large bone. Under microscopic examination, a high percentage (usually over 10%) of plasma cells confirms the diagnosis. The biopsy can also help distinguish multiple myeloma from other plasma cell disorders, such as monoclonal gammopathy of undetermined significance (MGUS) or plasmacytoma.
Additional tests, including cytogenetic analysis and fluorescence in situ hybridization (FISH), identify genetic abnormalities associated with prognosis and guide treatment strategies. In some cases, a biopsy of a lytic bone lesion or soft tissue mass may also be performed.
In summary, diagnosing multiple myeloma involves a comprehensive approach—combining clinical assessment, laboratory tests for abnormal proteins and organ function, advanced imaging to detect bone lesions, and confirmation via bone marrow biopsy. Early and accurate diagnosis enables timely intervention and tailored treatment plans, ultimately improving patient survival and quality of life.
