A 45-YEAR-OLD man complained of exercise-induced muscle pain, cramps, and stiffness. Muscle biopsy specimens revealed tubular aggregates (TAs) on light microscopy (Figure 1) and electron microscopy (Figure 2, A). Tubular aggregates may be found in various neuromuscular disorders1; they occur as irregular basophilic regions that are usually located at the edges in type II fibers (Figure 1).
van Engelen BGM, Ter Laak HJ. Tubular AggregatesTheir Continuity With Sarcoplasmic Reticulum. Arch Neurol. 1999;56(11):1410-1411. doi:10.1001/archneur.56.11.1410