Adult-Onset Nemaline Rods in a Patient Treated for Suspected Dermatomyositis

Abstract

• A 65-year-old woman with progressive muscle weakness and a diffuse rash of three years' duration was examined. Muscle tissue was studied with histochemical techniques, phase-contrast microscopy, electron microscopy, and twodimensional electrophoresis. Histochemical studies showed numerous nemaline rods, with a normal ratio of types I and II fibers. Two-dimensional electrophoresis revealed abnormalities in the myosin light chain and tropomyosin protein patterns when compared with normal and diseased muscle biopsy samples, including those from two patients with adult-onset dermatomyositis.