title: Magnetic resonance imaging helps in the early diagnosis of myositis ossificans in children.
abstract: Two cases on myositis ossificans circumscripta (MOC) in the arm are reported. Plain X-ray films and magnetic resonance imaging (MRI) were performed in both cases. In the first, an intramuscular tumor-like mass without calcifications was found on MRI with soft-tissue edema extension. In the second, MRI disclosed additional bone-marrow edema. The diagnosis of MOC was confirmed by biopsy in one case and by follow-up in the other. MOC is a benign soft-tissue lesion that is rare in children, with an acute course and usually spontaneously favorable evolution. The differential diagnosis from an infection or a malignant tumor remains difficult. The best imaging modalities are conventional radiography and MRI. The MRI patterns of MOC are typical but not pathognomonic; typical MRI findings in conjunction with clinical symptoms during the early phase of MOC permit the postponement of a biopsy or aggressive surgical procedures. Surgery is indicated for cases not showing typical MOC calcifications at a later stage.
authors.affiliation: Department of Radiology, Hôpital Universitaire des Enfants, Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Hanquinet
authors.forename: L
authors.initials: L
authors.lastname: Ngo
authors.forename: M
authors.initials: M
authors.lastname: Anooshiravani
authors.forename: J
authors.initials: J
authors.lastname: Garcia
authors.forename: P
authors.initials: P
authors.lastname: Bugmann
mesh_terms: D000293:Adolescent; D001132:Arm; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009221:Myositis Ossificans / Q000175:diagnosis*