Case Study 86 Leonidas Arvanitis, MD

Question 1: A 2-month-old male presents with severe hypotonia and weakness, cardiac and respiratory failure He also has a large tongue and feeding difficulties Describe the histologic findings on the H&E stains Click here to view H&E stains

Answer 1: Marked vacuolation of type 1 and type 2 myofibers

Question 2: Based on the most likely diagnosis what would a PAS stain show? Click here to view PAS stains

Answer 2: The vacuoles are strongly PAS positive

Question 3: Which other histochemical will strongly highlight the vacuoles?

Answer 3: Acid phosphatase Click here to view acid phosphatase stain

Question 4: What is your diagnosis?

Answer 5: Pompe's disease

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

Answer 6: Acid maltase a lysosomal enzyme which is responsible for hydrolyzing maltose, linear oligosaccharides and the outer chains of glycogen to glucose

Question 7: How many clinical subtypes of Pompe’s disease exist?

Answer 7: Severe infantile form Juvenile-onset form Adult-onset form

Question 8: What other organs can be affected?

Answer 8: Can involve heart, liver, kidney and CNS

Question 9: What would electron microscopy show?

Answer 9: Vacuolated myofibers with cytoplasmic glycogen accumulation and disruption of myofibrils