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Washington University Experience | MUSCLE | Myopathies with Mitochondrial Pathology | 35A2 (Case 35) EM083 - Copy

Inclusions in this image have dense cristae and parking lot inclusions. (electron micrograph) ---- Interpretation: Abnormal immune stains with diffusely increased MHC class I staining by all fibers, and subtle additional immune features in the center of the sample, including histiocytes adjacent to capillaries, and muscle fibers with mildly increased MxA staining. The findings remain compatible with an immune myopathy with regional myopathology, a pathologic subtype of immune myopathy common in patients with concurrent rash, TIF-1G antibodies, and a heightened risk for concurrent malignancy in adults (https://neuromuscular.wustl.edu/antibody/infmyop.htm#malignancy). ---- There is no mitochondrial pathology on COX or SDH. Findings warrant screening for occult/concurrent malignancy.

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