Case Study 87 Leonidas Arvanitis, MD

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

Answer 1: H&E stained sections show minimal changes

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

Answer 2: PAS Click here to view PAS stains

Question 3: Describe the PAS findings

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

Question 4: What is the most likely diagnosis?

Answer 4: McArdle disease

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

Answer 6: Myophosphorylase Patient (no staining) Control

Question 7 What would electron microscopy show?

Answer 7: Subsarcolemmal glycogen