Pathogenesis (disease development)
Plasmocytoma (multiple myeloma (MM)) regularly arises from monoclonal gammopathy of undetermined significance (MGUS), which progresses to MM or related disease in 1% of cases.
In plasmocytoma, malignant (malignant) transformation of plasma cells (cells of the immune system, they serve to produce and secrete antibodies) occurs, which in turn spread to the bone. The altered plasma cells produce monoclonal immunoglobulins (IgG, IgA, IgD), so-called paraproteins, or the Bence-Jones protein (light chains), which is produced in about 20% of cases. These cases are also referred to as “Bence-Jones plasmacytoma” or “light chain plasmacytoma”.Plasmacytoma cells stimulate osteoclasts (cells that break down bone substance), which lead to osteolytic foci (areas where bone breakdown occurs).
An increased risk for the development of multiple myeloma (precancerous condition) is the so-called monoclonal gammopathy of unclear significance (MGUS): paraproteinemia with monoclonal IgM globulins, without histological infiltration of the bone marrow with plasma cells or lymphoma cells (i.e., there is no plasmacytoma/multiple myeloma or Waldenström’s disease).MGUS is found in approximately 5% of people over 70 years of age in the German population.
A subtype of plasmacytoma is “smoldering multiple myeloma”. It is characterized by a slow progression and the absence of myeloma-typical skeletal changes, anemia or renal insufficiency. Bone marrow infiltration is <10% and paraprotein concentration is constant at 3 g/dL.The exact cause is largely unknown.The following factors are under discussion to be involved in pathogenesis (doctrine describing the onset and development of a disease with all factors involved).
Etiology (causes)
Biographical causes
- Genetic burden – Plasmacytoma is clustered in certain families, indicating a genetic component.
- Ethnicity – African American (>2-fold incidence rate).
- Occupations – more commonly affected groups of people:
- Workers in wood processing
- Workers in the leather industry
- Farmers
- Persons with exposure to mineral oil
Behavioral causes
- Nutrition
- Micronutrient deficiency (vital substances) – see Prevention with micronutrients.
- Overweight (BMI ≥ 25; obesity).
Environmental pollution – intoxications (poisoning).
- Ionizing radiation
- Exposure to mineral oil
