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Washington University Experience | MUSCLE | Myopathies with Mitochondrial Pathology | 12A1 Mitochondrial Myopathy (Case 12) EM 2 - Copy

Case 12 History ---- The patient is a 26 year old woman with myopathy and progressive bilateral ptosis and ophthalmoplegia for approximately twelve years, suggestive of a mitochondrial myopathy, such as Kearns Sayre progressive external ophthalmoplegia. Electromyographic findings are reported to be consistent with a mildly irritable myopathy. Operative procedure: Left biceps muscle biopsy. ---- 12A1,2 Examination of the muscle biopsy material shows mitochondrial abnormalities in a subset of muscle fibers. The abnormal mitochondria often appear in large groups beneath the sarcolemma. They are abnormally large and dark, misshapen with vacuolated cristae. Some mitochondria appear associated with autophagosomes. Another subset of mitochondria contain paracrystalline or 'parking lot' inclusions.

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