Light microscopy of the rectus femoris muscle. (A) Hematoxylin and eosin staining revealed extensive muscle fiber necrosis with prominent myofibrillar disarray. (B) ATPase (pH 9.4) reactions also revealed muscle fiber necrosis and decreased ATPase activity in type 2 fibers. (C) Modified Gomori trichrome staining revealed disarrayed muscle fibers without any ragged red fibers. (D) Oil red O staining revealed no heavy lipid deposition in the muscle fibers.