Glycogen complexes in muscle in Reye's syndrome simulating virus-like particles

Crystalline arrays of virus-like particles were present in the psoas muscle in six of eight autopsied cases of Reye's syndrome. These structures were concentrated in the perinuclear regions of peripheral muscle nuclei and were less abundant about the triad regions. The particles were stained by histochemical techniques for glycogen, and digestion with diastase resulted in removal of particles from these crystalline lattices. Virus-like particles were also present in crystalline arrays in psoas, quadriceps, and diaphragm muscles in six of eight autopsied cases of children and adults who died of diverse diseases. These configurations of glycogen in muscle appear to occur with the same frequency in various unrelated diseases and may be a cytochemical response to the generalized stress of disease. Recognition of their specific nature is important in differentiating them from viruses, especially in diseases of uncertain etiology.