title: Recurrent adult-type fibrosarcoma of the frontal bone in a child.
abstract: BACKGROUND
  Primary, adult-type bone fibrosarcoma is an uncommon, malignant spindle-cell tumor of fibroblastic origin, rarely affecting children. Most frequently diagnosed among bone malignancies in the past, improved diagnostic techniques and further restrictive classification criteria have currently made the diagnosis of fibrosarcoma very unusual.
  
  
  METHODS
  We hereby report the case of a 7-year-old child with a right frontal swelling mass. A computed tomography scan showed an osteolytic lesion of the right frontal bone, involving the diploe and the outer table of the skull. An en bloc surgical excision, followed by a thorough immunohistological evaluation, led to the diagnosis of fibroblastic proliferation, with low cellularity and minimal atypias. The patient had four recurrences during the 4-year follow-up. With an increasing histological grade at recurrences, a diagnosis of adult-type fibrosarcoma was made.
  
  
  CONCLUSIONS
  To the best of the authors' knowledge, this is the first reported case of an adult-type fibrosarcoma arising in the frontal bone of a child.
authors.affiliation: Department of Anatomic Pathology, Catholic University, Largo F. Vito 1, 00168, Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Novello
authors.affiliation: Pediatric Neurosurgery, Catholic University, Rome, Italy.|Pediatric Neurosurgery, International Neuroscience Institute, Hannover, Germany.
authors.forename: Concezio
authors.initials: C
authors.lastname: Di Rocco
authors.affiliation: Pediatric Neurosurgery, Catholic University, Rome, Italy.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Tamburrini
authors.affiliation: Pediatric Neurosurgery, Catholic University, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Frassanito
authors.affiliation: Pediatric Neurosurgery, International Neuroscience Institute, Hannover, Germany.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Aguirre
authors.affiliation: Division of Anatomic Pathology, Miller School of Medicine, University of Miami, Miami, FL, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Rosenberg
authors.affiliation: Department of Anatomic Pathology, Catholic University, Largo F. Vito 1, 00168, Rome, Italy. antonella.coli@rm.unicatt.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Coli
mesh_terms: D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology*; D002648:Child; D005354:Fibrosarcoma / Q000378:metabolism / Q000473:pathology*; D005624:Frontal Bone / Q000473:pathology*; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local
chemical_list: D019394:Ki-67 Antigen
keywords: Fibrosarcoma; Frontal bone; Immunohistochemistry; Molecular biology; Pediatric; Tumor progression