1. Case Study 87 Leonidas Arvanitis, MD

2. Question 1:
A 29-month-old female complains of myalgia and exercise intolerance
Her CK levels are variably increased
Describe the histologic findings on the H&E stains
Click here to view H&E stains

3. Answer 1:
H&E stained sections show minimal changes

4. Question 2:
What other stain might be helpful based on the H&E findings and the clinical history of this patient?

5. Answer 2:
PAS
Click here to view PAS stains

6. Question 3:
Describe the PAS findings

7. Answer 3:
PAS highlights subsarcolemmal accumulation of glycogen “blebs”

8. Question 4:
What is the most likely diagnosis?

9. Answer 4:
McArdle disease

10. Question 6:
Which enzyme is deficient in Pompe’s disease?

11. Answer 6:
Myophosphorylase
Patient
(no staining)
Control

12. Question 7
What would electron microscopy show?

13. Answer 7:
Subsarcolemmal glycogen