Tubular aggregates. Their association with neuromuscular diseases, including the syndrome of myalgias/cramps
N. L. Rosenberg, H. E. Neville and S. P. Ringel
Tubular aggregates of muscle are distinctive structures seen in a wide
variety of disorders. We reviewed 1,500 consecutive muscle biopsy specimens
for the presence of tubular aggregates. Fifteen biopsy specimens (1.0%)
were found with this abnormality. All patients were male, and seven had
specific diagnoses based on clinical, biochemical, morphologic, and
electrophysiologic criteria: hypokalemic periodic paralysis (two patients);
hyperkalemic periodic paralysis (one patient); myotonia congenita (one
patient); inflammatory myopathies (three patients). The remaining eight
patients had a syndrome characterized predominantly by muscle pain and/or
cramps, not necessarily precipitated by exercise. Although tubular
aggregates constituted the predominant abnormality on muscle biopsy
specimens in these cases, other mild, nonspecific changes were noted.
