Muscle Biopsy for Rhabdomyolysis and Elevated Creatine Kinase
Related narrative: Muscle Biopsy for Rhabdomyolysis
Elevated creatine kinase (CK) can be caused by hereditary or acquired disorders or by acute muscle damage. Muscular dystrophy and rhabdomyolysis are incuded amongst the causes of an elevated (CK).
Rhabdomyolysis is defined as muscle necrosis and is characterized pathologically as compromised integrity of the skeletal muscle sarcolemma.
The differential diagnosis for rhabdomysis is quite broad and can be divided into inherited and acquired causes.
The inherited causes include deficiencies of glycogenolyic and glycolytic enzymes (e.g. McArdle's disease), abnormal lipid metabolism (e.g. carnitine palmitoyltransferase deficiency), myoadenylate deaminase deficiency, malignant hyperthermia, neuroleptic malignant syndrome, myopathy, and muscular dystrophy.
Three specimens of vastus lateralus were obtained. The specimen preserved in formaldehyde was prepared with HandE, pas, and trichrome stains, the specimen preserved in gluteraldehyde was examined by electron microscopy to look for sarcolema disruption, and the specimen sent wrapped in saline-moistened gauze was analyzed by immunohistochemistry.
HandE is used to assess for muscle fiber pathology, trichrome stain is more specific for connective tissue pathology, while PAS looks at glycogen status.
The targets of the immunohistochemical analysis are as follows:
emerin (absent in Emery-Dreifuss muscular dystrophy)
merosin (absent in congenital muscular dystrophy)
phosphorylase (deficient in McArdle's disease)
cytochrome c oxidase (deficient in mitochondrial disorders)
succinate dehydrogenase (deficient in mitochondrial Kreb's cycle disorders)
esterase (neuromuscular and myotendinous junction pathology)
alkaline phosphatase (regenerating muscle fibers)
major histocompatibility complex-1 (expressed on phagocytes found in muscle fibers in myositis)
nicotinamide adenine dinucteotide (abnormal internal muscle fiber architecture)
dystrophin proteins (associated with muscular dystrophies)
sarceoglycan (dystrophin-associated muscle membran protein)
myophosphorylase (deficient in McArdle's disease)
myoadenylate deaminase (deficient in hereditary myopathies)
adenosine triphosphate (depleted in malignant hyperthermia and metabolic disorders)
Clinical Neurol Neurosurg 95: 175-192. 1993.
Joshua Kindelan, M.D.