title: Primary High-Grade Osteosarcoma of the Clivus: A Case Report and Literature Review.
abstract: BACKGROUND
  Osteosarcoma is the second most common primary tumor of the skeletal system and the most common primary bone tumor. Usually occurring at the metaphysis of long bones, osteosarcomas are highly aggressive lesions that comprise osteoid-producing spindle cells. Craniofacial osteosarcomas comprise <8% and are believed to be less aggressive and lower grade. Primary osteosarcomas of the skull and skull base comprise <2% of all skull tumors. Osteosarcomas originating from the clivus are rare. We present a case of a primar, high-grade clival osteosarcoma.
  
  
  METHODS
  A 29-year-old man presented to our institution with a progressively worsening right frontal headache for 3 weeks. There were no sensory or cranial nerve deficits. Computed tomography revealed a destructive mass involving the clivus with extension into the left sphenoid sinus. Magnetic resonance imaging revealed a homogenously enhancing lesion measuring 2.7 × 2.5 × 3.2 cm. The patient underwent endonasal transphenoidal surgery for gross total resection. The histopathologic analysis revealed proliferation of malignant-appearing spindled and epithelioid cells with associated osteoclast-like giant cells and a small area of osteoid production. The analysis was consistent with high-grade osteosarcoma. The patient did well and was discharged on postoperative day 2. He was referred for adjuvant radiation therapy and chemotherapy. Two-year follow-up showed postoperative changes and clival expansion caused by packing material.
  
  
  CONCLUSIONS
  Osteosarcoma is a highly malignant neoplasm. These lesions are usually found in the extremities; however, they may rarely present in the craniofacial region. Clival osteosarcomas are relatively infrequent. We present a case of a primary clival osteosarcoma with high-grade pathology.
authors.affiliation: Department of Neurosurgery, Ochsner Health System, New Orleans, Louisiana, USA; Department of Neurosurgery, Tulane Medical Center, New Orleans, Louisiana, USA. Electronic address: mmathkour@outlook.com.
authors.forename: Mansour
authors.initials: M
authors.lastname: Mathkour
authors.affiliation: Department of Neurosurgery, Ochsner Health System, New Orleans, Louisiana, USA; Department of Neurosurgery, Tulane Medical Center, New Orleans, Louisiana, USA.
authors.forename: Juanita
authors.initials: J
authors.lastname: Garces
authors.affiliation: Department of Neurosurgery, Tulane Medical Center, New Orleans, Louisiana, USA.
authors.forename: Bryce
authors.initials: B
authors.lastname: Beard
authors.affiliation: Department of Neurosurgery, Ochsner Health System, New Orleans, Louisiana, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Bartholomew
authors.affiliation: Department of Neurosurgery, Ochsner Health System, New Orleans, Louisiana, USA.
authors.forename: Olawale A R
authors.initials: OA
authors.lastname: Sulaiman
authors.affiliation: Department of Neurosurgery, Ochsner Health System, New Orleans, Louisiana, USA.
authors.forename: Marcus L
authors.initials: ML
authors.lastname: Ware
mesh_terms: D000328:Adult; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods*; D009666:Nose / Q000601:surgery; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000601:surgery*; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D015898:Tomography Scanners, X-Ray Computed
keywords: Clival osteosarcoma; Endonasal transphenoidal approach; Primary high-grade osteosarcoma; Sellar osteosarcoma; Skull base osteosarcoma