My Orthopaedic Surgeon

Deltoid fibrosis is a muscle disorder marked by intramuscular fibrous bands within the substance of the deltoid muscle. These bands lead to secondary contractures that affect the function of the shoulder joint. Scapular winging and secondary scoliosis also may be related to this condition. Deltoid fibrosis has been associated with fibrous contractures of the gluteal and quadriceps muscles and is likely a similar process.
Reports of deltoid fibrosis began in the early 1960s. I Isolated descriptions of the condition had been documented prior to that but not in the English literature. Following World War II, parenteral administration of antibiotics, antipyretics, and other drugs became increasingly common. Along with the increased use of intramuscular injections came the appearance of deltoid fibrosis and contractures, as well as problems in other muscle groups.
Author: Mark Brodersen, MD 2005

Discussion: - benign condition usually occuring in adults, but sometimes in children; - may present as a rapidly growing mass, in the shoulder, thigh, and chest; - Histology: - should not show mitotic figures;