Multiple myeloma is a cancer of plasma cells, which are a type of white blood cell found in the bone marrow. While there's one primary type of multiple myeloma, the disease can be classified based on the type of abnormal protein (monoclonal protein, or M-protein) produced by the myeloma cells or based on its stage and the presence of particular features. Here's a list of multiple myeloma types and related conditions:

Secretory Multiple Myeloma: This is the most common type. In this form, myeloma cells produce an M-protein, which can be found in the blood or urine. The specific types of M-proteins include:

  • IgG Myeloma: The most common subtype, accounting for about 50% to 60% of cases.
  • IgA Myeloma: Represents about 20% to 30% of cases.
  • IgD Myeloma: Quite rare, accounting for less than 2% of cases.
  • IgE Myeloma: Extremely rare.
  • IgM Myeloma: Also very rare and is sometimes classified as a type of Waldenstr√∂m macroglobulinemia, another plasma cell disorder.
  • Light Chain Myeloma: In this subtype, only the light chains of the immunoglobulin (often referred to as kappa or lambda) are produced.
  • Non-Secretory Multiple Myeloma: In about 3% of cases, myeloma cells do not produce detectable levels of M-proteins in the blood or urine.
  • Smoldering (Asymptomatic) Multiple Myeloma: This is an early stage of the disease where patients have elevated levels of M-protein and abnormal plasma cells in the bone marrow but no other signs or symptoms of active myeloma. It has the potential to progress to active myeloma.
  • Solitary Plasmacytoma: This is a single isolated tumor of abnormal plasma cells that can be located in bone (solitary bone plasmacytoma) or soft tissue (extramedullary plasmacytoma). It has the potential to progress to widespread multiple myeloma.
  • Plasma Cell Leukemia: A rare and aggressive form in which myeloma cells are found in the bloodstream.
  • Extramedullary Myeloma: In this form, myeloma cells form tumors in tissues outside the bone marrow, such as skin, muscles, or lungs.
  • High-Risk Multiple Myeloma: This classification is based on certain genetic abnormalities that suggest a more aggressive disease course.

Related Plasma Cell Disorders:

Monoclonal Gammopathy of Undetermined Significance (MGUS): A benign condition where M-proteins are found in the blood, but there are no symptoms of multiple myeloma. MGUS can progress to multiple myeloma or other diseases, so regular monitoring is essential.

Each type or stage of multiple myeloma and related conditions has its unique characteristics and treatment considerations. If you or someone you know is affected by multiple myeloma, consulting with a hematologist or oncologist is crucial for accurate diagnosis and guidance on the most appropriate treatments.