Delve into the pathophysiology of multiple myeloma, a proliferative disorder of plasma cells which is the second most common hematological malignancy. It explains the development from normal B cells in the bone marrow to uncontrolled plasma cells producing large amounts of antibodies and monoclonal proteins. The video covers the spectrum of plasma cell dyscrasias, stages of progression, and introduces the CRAB criteria used for diagnosing symptomatic multiple myeloma. Detailed discussions on diagnosis, various symptoms, and treatment options, including newer non-chemotherapy regimens and gene therapies, provide a comprehensive overview of managing this complex cancer.