plasmacytoma
Meaning of plasmacytoma: A single collection of abnormal antibody-making cells, which may stay solitary or prove to be the first sign of myeloma.
Definition of plasmacytoma
A plasmacytoma is a tumor made of plasma cells, the mature white blood cells that manufacture antibodies. Unlike multiple myeloma, which involves marrow throughout the skeleton, a plasmacytoma forms one discrete mass. It grows most often inside a bone, particularly a vertebra, and less often in soft tissue such as the lining of the nose, sinuses or throat.
What are plasma cells?
They are the final form of a B lymphocyte. When a B cell meets the molecule it was built to recognize, it matures into a plasma cell and becomes a factory, producing a single antibody in large quantity. Most live in the bone marrow. The name refers to these cells and not to plasma, the liquid part of blood, although both words trace back to the same root meaning something molded.
What types are there?
| Type | Where it sits | Usual behavior |
|---|---|---|
| Solitary plasmacytoma of bone | Vertebra, rib, pelvis, long bone | Frequently progresses to myeloma |
| Extramedullary plasmacytoma | Soft tissue, mostly nose, sinuses and throat | Less often progresses |
How does it relate to myeloma?
They are the same disease process at different extents. A plasmacytoma is one deposit; multiple myeloma is the same abnormal clone established throughout the marrow, with the anemia, bone destruction, kidney impairment and raised calcium that follow. Establishing which is present decides treatment, so assessment includes examination of the marrow, imaging of the whole skeleton, and tests for abnormal antibody protein in blood and urine. A single lesion with a normal marrow and no organ damage is treated as solitary, usually with radiation to that site, and followed closely afterward, since a proportion declare themselves as myeloma over the following years.
What symptoms does it cause?
A bone lesion typically causes persistent, localized pain that does not ease with rest, and it can weaken the bone enough to break under ordinary load. In a vertebra, collapse can press on the spinal cord and produce weakness or numbness in the legs. A soft tissue lesion in the nose or throat causes blockage, a change in voice, or bleeding.
Also known as
Used in a sentence
Radiotherapy was directed to a solitary plasmacytoma involving the fifth thoracic vertebra.
Good to know
A solitary plasmacytoma is distinguished from multiple myeloma by marrow examination, skeletal imaging and protein testing, and a substantial share progress to myeloma over time.
Word origin
Where “plasmacytoma” comes from
Combines plasma, from the Greek for something molded, with kytos, meaning cell, and -oma, denoting a tumor.