title: Extra-osseous osteochondroma-like soft tissue mass of the patello-femoral space.
abstract: BACKGROUND
  Extraskeletal cartilaginous tumors are uncommon. Osteochondromas usually arise from the metaphyseal region of the growing skeleton.
  
  
  METHODS
  A 53 year old man presented with a three years history of anterior knee pain and inability to flex his knee more than 90 degrees . Clinical examination and imaging studies revealed a nodular calcific mass in the anterior portion of the knee, displacing the medial portion of the patellar tendon. Following excision, histopathology confirmed the diagnosis of extra-osseous osteochondroma-like soft tissue mass, with no recurrence 24 months after surgery.
  
  
  CONCLUSIONS
  An integrated clinical-pathologic diagnosis helps to clarify the nature of extraskeletal cartilaginous tumors that can arise at unusual anatomic site. Complete local surgical excision is the management of choice.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Rome Tor Vergata School of Medicine, Viale Oxford 81, Rome, Italy. olivafrancesco@hotmail.com
authors.forename: Francesco
authors.initials: F
authors.lastname: Oliva
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marconi
authors.forename: Stefano
authors.initials: S
authors.lastname: Fratoni
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
mesh_terms: D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015831:Osteochondroma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery