title: Myositis ossificans circumscripta without history of trauma.
abstract: Myositis ossificans circumscripta is a form of heterotopic ossification that is benign in nature associated to a trauma, but may appear clinically and radiologically as a malignant neoplasm. We describe a rare case of calcifying of myositis ossificans not associated to trauma in a 35-year-old woman with a mass in her upper third and external of right thigh. We discuss some of the difficulties of diagnosis and histological evolution of the lesion.
  
  
  BACKGROUND
  Myositis ossificans; Thigh; Differential diagnosis; Nontraumatic.
authors.affiliation: Department of Pathology, University Hospital, Granada, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Aneiros-Fernandez
authors.forename: Mercedes
authors.initials: M
authors.lastname: Caba-Molina
authors.forename: Salvador
authors.initials: S
authors.lastname: Arias-Santiago
authors.forename: Francisco
authors.initials: F
authors.lastname: Ovalle
authors.forename: Pedro
authors.initials: P
authors.lastname: Hernandez-Cortes
authors.forename: Jose
authors.initials: J
authors.lastname: Aneiros-Cachaza