[5 cases of stress myalgia with tubular aggregates]

The authors report 5 cases of stress myalgias associated with tubular aggregates seen in muscle biopsy specimens. A few similar cases are reported in the literature and a close relationship is established by some authors between the morphologic anomaly present in type II fibers and the lack of tolerance to stress. However, tubular aggregates are not specific and found in other disorders, especially the hyperkaliemic periodic paralysis where all types of fibers are affected. The origin of the aggregates is unknown. They could come from the endoplasmic reticulum containing an excess of calcium and form aggregates in order to prevent a muscle contraction.