A 63-year-old man comes to the physician for a follow-up appointment. He has had intermittent headache for the past two months and occasional blurry vision. For the past week he has had increased diffuse bodily itching following his nightly shower. Laboratory studies show:
Hemoglobin 18.0 g/dL
Leukocytes 14,000/μL
Platelets 300,000/μL
Serum calcium 9.0 mg/dL
Which of the following is most likely to be seen in this patient?
A) Decreased erythropoietin
B) Kappa light chain IgM spike
C) Lambda light chain IgG spike
D) Nephrotic syndrome
E) Serum basophils of 1.0%
