Which CBC finding is commonly associated with multiple myeloma?

Which CBC finding is commonly associated with multiple myeloma?

• A. Macrocytosis
• B. Hemolysis
• C. Target cells
• D. Rouleaux formation on CBC

Answer: (D)

Rouleaux formation on the CBC is a hallmark of hyperproteinemia from a plasma cell disorder like multiple myeloma. When malignant plasma cells produce a large amount of monoclonal immunoglobulin, the excess proteins coat red blood cells, reducing their surface charge and allowing them to stack together in coin-like formations. This stacking is seen on a CBC as rouleaux and is often accompanied by a markedly elevated ESR. Think of it this way: the big surge in circulating proteins changes the way red blood cells interact, so they tend to clump in orderly stacks rather than float freely. The other options point to different red cell abnormalities not specific to multiple myeloma—macrocytosis suggests vitamin deficiencies or alcohol effects, hemolysis implies red cell destruction, and target cells are typical of liver disease or certain hemoglobinopathies. The rouleaux pattern best fits the scenario of multiple myeloma.

Rouleaux formation on the CBC is a hallmark of hyperproteinemia from a plasma cell disorder like multiple myeloma. When malignant plasma cells produce a large amount of monoclonal immunoglobulin, the excess proteins coat red blood cells, reducing their surface charge and allowing them to stack together in coin-like formations. This stacking is seen on a CBC as rouleaux and is often accompanied by a markedly elevated ESR.

Think of it this way: the big surge in circulating proteins changes the way red blood cells interact, so they tend to clump in orderly stacks rather than float freely. The other options point to different red cell abnormalities not specific to multiple myeloma—macrocytosis suggests vitamin deficiencies or alcohol effects, hemolysis implies red cell destruction, and target cells are typical of liver disease or certain hemoglobinopathies. The rouleaux pattern best fits the scenario of multiple myeloma.