Sporadic early adult-onset distal myopathy with rimmed vacuoles: immunohistochemistry and electron microscopy.
We report the histoenzymology, immunohistochemistry and electron microscopy of the tibialis anterior muscle of a 50-year-old male patient affected by a sporadic distal myopathy with onset during adolescence. There was no family history of muscle disorder and no clinical signs of cardiomyopathy. Extremely large variations in muscle fibre diameter (the size of some fibres exceeding 200-250 microns), rimmed vacuoles, necrotic fibres invaded by macrophages, atrophic fibres and perimysial fibrosis were observed. Using a wide range of antibodies raised against membrane- and cytoskeletal muscle proteins, granular desmin immunoreactivity was observed in muscle fibre lesions. There were no inflammatory parameters. Of special interest was the occurrence of autophagic vacuoles without 18-20 nm thick sarcoplasmic filaments and the presence of small aggregates of intermediate desmin-like filaments among a great diversity of ultrastructural findings. The morphological differential diagnosis is discussed. Our results stress the importance of combined immunohistochemistry and electron microscopy in the delineation of distal myopathies. DNA defects, however, still have to be identified which would improve the present classifications of distal myopathies.
Ceuterick
C
C
Born-Bunge Foundation and University of Antwerp (UIA), Department of Neuropathology, Antwerpen, Belgium.
Martin
J J
JJ
D003598:Cytoskeletal Proteins / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D008854:Microscopy, Electron; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009124:Muscle Proteins / Q000032:analysis / Q000172:deficiency*; D009135:Muscular Diseases / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D009336:Necrosis; D014617:Vacuoles / Q000648:ultrastructure*
D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins