Polymyositis with tubular aggregates.

We report a patient with classic idiopathic polymyositis who had tubular aggregates on muscle biopsy. Tubular aggregates are distinctly rare in polymyositis although seen in a variety of other muscle disorders including myopathies associated with muscle cramping. Our patient did not have muscle cramps or severe myalgia. Moreover, the patient's disease responded to steroids, indicating that tubular aggregates were not a marker for steroid resistance. The function of the tubular aggregates in this disease is not clear.