Question

What is NOT true about multiple myeloma?

• A. It is more common in those over 50 years of age
• B. It arises from clones of plasma cells
• C. Bence Jones proteins are abnormal whole immunoglobulins found in urine
• D. There is a predisposition to amyloidosis

Hint:

Remember what a Bence Jones protein actually is: a free light chain, not a full antibody.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We need to pick the one statement about multiple myeloma that is false.

Step 2: Key Concept:
Multiple myeloma is a cancer of plasma cells, the antibody-making cells of the bone marrow. A single abnormal plasma cell multiplies into a clone, and that clone churns out one type of antibody or antibody fragment in huge amounts.

Step 3: Detailed Explanation:
Multiple myeloma is indeed a disease of older adults, most often diagnosed after age 50, so this statement is true.
It truly arises from a clone of plasma cells, all descended from one transformed cell, so this statement is also true.
Bence Jones proteins are not whole antibody molecules. A whole immunoglobulin has two heavy chains and two light chains joined together. In myeloma, the clone often makes far more light chains than heavy chains, and the extra free light chains are small enough to pass through the kidney filter into urine. That is exactly what a Bence Jones protein is, a free light chain, not a whole immunoglobulin. So calling it a whole Ig is wrong, which makes this statement false.
Myeloma does raise the risk of amyloidosis, because the excess light chains can misfold and deposit as amyloid in tissues (AL amyloidosis), so this last statement is true.

Step 4: Final Answer:
The false statement is that Bence Jones proteins are abnormal whole immunoglobulins.