Extensive Osteosarcoma of the Craniocervical Junction in a Young Patient: Diagnosis and Treatment Considerations

Background Osteosarcoma is the most common malignancy of bone found in the pediatric and adolescent population. Osteosarcoma is very rare, with an incidence of 1:100,000 per year, and a peak age between 10 and 14 years, when bone turnover is at its peak during the adolescent growth spurt. The most common sites are in the appendicular skeleton. About 10% of osteosarcomas can be found in the head and neck, usually in the mandible or maxilla, and less commonly in other bones. Since the 1970s, there have been ∼120 cases reported of osteosarcomas of the skull base. We present a case of osteosarcoma with massive destruction of the craniocervical junction.

Case Presentation A 23-year-old right-handed Caucasian woman with a history of allergies and sinusitis initially presented to a community ENT with earache, aural fullness, and right-sided headache for 1 month. An empirical diagnosis of eustachian tube dysfunction was made, and she was given oral steroids and antibiotics, which did not improve her symptoms. Upon follow-up, her headaches had worsened and were now accompanied by dizziness, right-sided paresthesias, and right-sided tongue deviation. MRI and CT were performed, which showed a highly destructive mass in the right occiput and petrous apex, extending into the cerebellopontine angle laterally and the clivus bilaterally, with additional involvement of the upper C-spine. She was referred for surgical evaluation to our team, including an endoscopic skull base surgeon, neurosurgeon, and neuro-otologist.

At the time of her presentation to our clinic, about 6 months after onset of pain, she complained of blurry vision, tongue weakness, and dysphagia, in addition to her initial symptoms of headaches, otalgia, neck pain, and dizziness. We suspected aggressive malignancy. CT/PET revealed no lesions outside the skull base. We attempted a conservative approach to biopsy, with two separate CT-guided needle biopsies, which were nondiagnostic. Next, we performed an endonasal endoscopic approach through the floor of the sphenoid sinus for biopsy of the clivus, which ultimately confirmed her diagnosis.

Discussion Osteosarcoma is a highly aggressive malignancy with poor prognosis. The mainstays of treatment are surgical resection (when feasible and when morbidity is acceptable), followed by chemotherapy and radiation in most cases.

On anatomic grounds, a surgical resection in this case would have require removal of the entire right occipital bone, most of the temporal bone, the entire clivus, and part of the contralateral occiput as well as part of C1. The jugular foramen and foramen magnum were both extensively involved, with both intra- and extradural tumors. Complete resection with oncologically meaningful margins was, in our judgment, not feasible. In addition, a major concern was the instability of the C-spine. Our recommendation was to perform external occipital-spinal fusion and then begin chemotherapy and radiation.

At this writing, the patient is currently receiving chemotherapy and experiencing progressive dysphagia and hoarseness. Diagnosis, imaging, surgical considerations, and adjuvant treatments will be discussed in the article.