desmin cardiomyopathy
Synopsis
diffuse myocyte hypertrophy
nuclear pleomorphism without intramyocardial fibrosis
myofibers distorted by intracytoplasmic, pale, waxy hyaline inclusions
conduction fibers grossly swollen and preferentially involved
trichrome stain
- pale pink inclusions against a red background
inclusions PAS negative and not congophilic
Immunochemistry
desmin immunohistochemical staining variable
- dense staining of inclusions in some areas
- faint to no staining
Electron microscopy
filamentous and fibrillar inclusions
streaming disruption of Z-bands is prominent
inclusions pushing the myofilaments aside and disrupting the cytoplasm with accumulation of mitochondria against the cell membrane
inclusions containing conspicuous Z-band material
+/- endoplasmic reticular structures
Etiology
desmin gene mutations
Case records
See also
myofibrillar myopathies