Abnormal skeletal muscle morphology Skeletal muscle fibrosis 2017-01-13T22:27:25Z Muscle biopsy: fibrosis Excessive formation of fibrous bands of scar tissue in between muscle fibers. Pathophysiologic fibrosis, which is essentially an excessive accumulation of extracellular matrix components, particularly collagen, is the end result of a cascade of events proceeding from tissue injury via inflammation, and resulting in permanent scar formation. Fibrosis can impair tissue function. In skeletal muscle, fibrosis is most often associated with the muscular dystrophies.