A 75 y/o man with history of Hypertension, Pagets disease and peripheral vascular disease presents to you with complaints of chronic hearing impairment on right side. He is otherwise physically very active. Physical examination benign except for right sided sensorineural hearing deficit A skull x-ray was obtained to evaluate his paget’s disease.Lab studies reveal hemoglobin of 9.7, platelets 310, wbc 10k with normal differential, BUN 38, creatinine 1.4, calcium of 11.2. The patient is currently on alendronate for Pagets disease.
Which of the lab measure or imaging would usually be expected to be abnormal in the condition that is responsible for his skull x-ray findings and hypercalcemia?
A. Alkaline phosphatase
B. Serum Immunoelectrophoresis
C. Bone Scan
D. Carcino Embryonic Antigen
E. CA-15-3
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b
Ans. B
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Pagets disease history is a distractor in this case. Paget’s disease does not cause hypercalcemia unless the patient is immobilized because of poor control. The hypercalcemia in paget’s is secondary to prolonged immobilization not because of Paget’s per se. This patient is physically very active. The question is asking what is the usual abnormality seen in patients with MM. Because only MM explains his renal insufficiency, punched out lesions in the skull and hypercalcemia.The question also presents a skull radiograph that shows “Osteolytic” lesions with out any concomitant “Osteoblastic” process. Such pure osteolytic lesions are hallmark of MM which is why Alkaline phosphatase and Bone scans are often normal in MM. ( Recognize that Osteoblasts are the ones that are responsible for positive bone scan and increased alkaline phosphatase and hence, these are normal in MM which has no osteoblastic activity in skeletal lesions) .
Serum and Urine electrophoresis with immunofixation may reveal a monoclonal spike and useful for confirmation of the diagnosis. Patient also has hypercalcemia, anemia and renal insufficiency which are associated features in multiple myeloma.
Paget’s disease, on the other hand, is charecterized by mixed osteolytic and osteoblastic phases. Alkaline phosphatase is typically elevated in patients with Pagets. The skull radiograph will show a “cotton wool” appearance caused by irregular areas of sclerosis
( mixed lytic areas with blastic areas).
A phosp alkalina it is a turover of the bone, high resorption of bone
nice
informative
Does this mean that the pt may have been previously incorrectly dx with Paget’s dz when he was really suffering from MM?
No, he does have a history of Paget’s disease which is chronic and as a result, he also has hearing deficit. The problem is currently having and his skull x-ray findings are unrelated to Paget’s . Paget’s history is just a dis tractor. The question aims to test your understanding of clinical presentation of paraproteinemias and MM.
This is a really good question. Thanks!
PUNCHED OUT LESIONS ON XRAY CLASSIC !
Thanks for posting such a nice question with so elaboratie and informative explanation. But the fact is pt is still suffering from pagets (not cured yet) and so his alkaline phosphatase level should be elevated also at this point.
A
It’s really very good question
MM
multiple myeloma
MM