Muscle pain syndromes and fibromyalgia: the role of muscle biopsy

Muscle pain syndromes are extremely frequent cause of chronic disability, and a muscle biopsy is often performed to achieve a diagnosis when myalgia has a myopatic origin. Instead, the role of muscle biopsy in fibromyalgia is controversial. This review examines the reported studies with the objective to evaluate if some changes exist in the muscle, if these changes produce pain and if muscle biopsy is helpful in diagnostic flowchart of fibromyalgia.