Retro-odontoid pseudotumor without atlantoaxial subluxation

Area of Science:

• Neurosurgery
• Spinal Surgery
• Radiology

Background:

• Retro-odontoid pseudotumors (ROP) are rare lesions often associated with atlantoaxial instability.
• Atlantoaxial subluxation (AAS) is a common finding in patients diagnosed with ROP.

Observation:

• A 72-year-old male presented with gait disturbance and progressive quadriparesis.
• Imaging revealed a retro-odontoid mass causing severe cervical spinal cord compression, but dynamic radiography excluded AAS.
• CT demonstrated spondylotic changes and facet fusion, with abnormal C1-C2 mobility.

Findings:

• Intraoperative pathology confirmed the lesion as a pseudotumor.
• Posterior C1-C2 fixation was performed, leading to significant ROP reduction on follow-up MRI.
• This case represents an unusual ROP presentation without concurrent AAS.

Implications:

• This case expands the understanding of ROP presentations, demonstrating that AAS is not a universal prerequisite.
• Surgical intervention, including C1-C2 fixation, can be effective in managing ROP even in the absence of AAS.
• Further research into the etiology and management of ROP without AAS is warranted.