Reversible vacuolar myopathy of type II fibers

A 23-year-old ex-bicycle racer with vague gastrointestinal symptoms had an acute weight loss of 13.6 kg (30 lb). During the period of maximal weight loss, he experienced muscle weakness, dysphagia, bradycardia, and T wave changes on the electrocardiogram. His skeletal muscle biopsy showed a severe vacuolar myopathy devastating the atrophic type II fibers. Without treatment, he recovered completely and has remained well. This may be an exaggerated or acute form of type II atrophy not previously reported, or it may represent an acute muscular degeneration.