| Description |
This is one of the mature B cell dyscrasias
and is composed of plasma cells. The disease is known for its lytic
bone lesions but invasion of other tissues such as skin and lymph node
ocurs. The cells are dependent on IL-6 for growth. There is
an association with human herpes virus 8, which produces an IL-6 like product.
Mott cells are plasma cells containing blue-staining droplets of Ig in
their cytoplasm. In addition, on PAS stain, inclusions of Ig can
be seen in the nucleus (Dutcher bodies) and the cytoplasm (Russell bodies).
Bence-Jones (light chain) proteinuria is often present. Hypercalcemia
results from osteolysis, and may result in symptoms such as neurological
changes, constipation, and polyuria. The cause of death in these
patients is usually infection or renal insufficiency (secondary to the
BJ proteinuria and amyloidic deposits). The most common M protein
produced in multiple myeloma is IgG, followed by IgA. |
