Table of Contents

Washington University Experience | MUSCLE | Myopathies with Mitochondrial Pathology | 32A1A (Case 32) EM058 - CopyA

Case 32 History ---- The patient is a 5-year-old girl with lifelong GI motility issues, chronic visceral hyperalgesia, CVID on IVIg, and OSA on CPAP. The patient was referred by CHOP for a muscle biopsy to evaluate for a mitochondrial DNA deletion disorder. ---- 32A1A-E Ultrastructure shows a predominant pattern consisting of numerous mitochondria both within individual muscle fibers in the sarcoplasm and in the pale subsarcolemmal blebs. There are large collections of mitochondria which vary significantly in number, size and shape. The largest mitochondria have diameters 5-10X or more the size of normal mitochondria. Internal contents of individual mitochondria include matrix densities as well as dark cristae which appear simplified and larger than normal cristae. Lipid droplets were intimately associated with clumps and individual mitochondria. There were scattered cytosomes with the appearance of lipopigment with granular cytoplasmic content. Mitophagy is not part of the ultrastructural appearance of these cytosomes. There were no “parking lots” or ringed mitochondria. There were very rare pale fibers which appear to show myosin loss myopathy.

---