Plasma cell (multiple) myeloma may be suspected if which of the following is seen on a peripheral smear?

Plasma cell (multiple) myeloma may be suspected if which of the following is seen on a peripheral smear?

• A. Rouleaux
• B. Auer rods
• C. Spherocytes
• D. Schistocytes

Answer: (A)

Rouleaux formation on a smear reflects increased serum proteins that reduce the charge repulsion between red blood cells, causing them to stack like coins. In plasma cell myeloma, malignant plasma cells overproduce monoclonal immunoglobulin (M protein), elevating serum protein levels and promoting rouleaux. This clue on the smear supports suspicion for hyperproteinemia associated with multiple myeloma, especially when paired with compatible clinical findings. Other options are not typical for myeloma: Auer rods are seen in acute myeloid leukemia, not in myeloma; spherocytes arise from membrane loss in conditions like hereditary spherocytosis or autoimmune hemolytic anemia; schistocytes come from mechanical destruction in microangiopathic hemolysis, not from myeloma.

Rouleaux formation on a smear reflects increased serum proteins that reduce the charge repulsion between red blood cells, causing them to stack like coins. In plasma cell myeloma, malignant plasma cells overproduce monoclonal immunoglobulin (M protein), elevating serum protein levels and promoting rouleaux. This clue on the smear supports suspicion for hyperproteinemia associated with multiple myeloma, especially when paired with compatible clinical findings. Other options are not typical for myeloma: Auer rods are seen in acute myeloid leukemia, not in myeloma; spherocytes arise from membrane loss in conditions like hereditary spherocytosis or autoimmune hemolytic anemia; schistocytes come from mechanical destruction in microangiopathic hemolysis, not from myeloma.