myeloma

Definition

Cancer that arises in the bone marrow and involves plasma cells, a type of white blood cell that produces proteins called immunoglobulins.

A neoplasm characterized by cells normally found in the bone marrow.

1. a B lymphocyte tumor.
2. multiple myeloma.

• giant cell m. — giant cell tumor (1).
• multiple m. — a malignant neoplasm of plasma cells, in which the plasma cells proliferate and invade the bone marrow, causing destruction of the bone and resulting in pathological fracture and bone pain. A secretory form of the disease is characterized by the presence of an immunoglobulin recognized as Bence Jones protein (monoclonal immunoglobulin), Bence Jones proteinuria, anemia, and lowered resistance to infection. It is the most common type of monoclonal gammopathy. A non-secretory form of the disease also occurs.
• osteosclerotic m. — multiple myeloma associated with osteosclerosis (rather than bone destruction) and often with peripheral neuropathy.
• plasma cell m. — see multiple myeloma (above).
• m. protein — the immunoglobulin molecules produced by myeloma cells. See gammopathy.