Myelom

Myeloma refers to cancers arising from plasma cells in the bone marrow. The most common form is multiple myeloma, where malignant plasma cells accumulate and often produce a monoclonal protein. Related disorders include solitary plasmacytoma, smoldering myeloma, and rarely plasma cell leukemia.

Pathophysiology: Malignant plasma cells disrupt normal marrow function, promote bone loss with lytic lesions, and secrete abnormal antibodies or light chains that can damage kidneys and impair immunity. The disease may evolve over years and cause end-organ damage.

Symptoms: Bone pain, fatigue from anemia, frequent infections, and signs of high calcium or kidney problems. Some cases are found incidentally through abnormal tests or imaging.

Diagnosis and staging: Diagnosis requires clonal plasma cells in the marrow and evidence of organ damage or biomarkers. Tests include serum and urine immunofixation, free light chains, marrow biopsy, and imaging (X-ray, MRI, CT, or PET-CT). Staging uses ISS or the Revised ISS (R-ISS), incorporating measures such as beta-2 microglobulin, albumin, LDH, and cytogenetics.

Treatment: Active disease is treated with systemic therapy, typically a combination of a proteasome inhibitor, an immunomodulatory drug, and dexamethasone, with monoclonal antibodies as appropriate. Autologous stem cell transplantation is common for eligible patients. Local radiotherapy helps focal bone lesions; supportive care addresses anemia, infections, and kidney function.

Prognosis and epidemiology: Myeloma mainly affects older adults and is more common in men. Survival has improved with new therapies, but outcomes vary with stage, genetics, and treatment response.