Retro-odontoid soft tissue mass associated with atlantoaxial subluxation in an elderly patient: A case report

BACKGROUND We present the case of an elderly patient with a retro-odontoid soft tissue mass associated with atlanto-axial subluxation. CASE DESCRIPTION A 74-year-old man was admitted to our hospital with progressive motor weakn ess in his right arm and neck pain. Radiological examinations revealed atla ntoaxial subluxation and diffuse degenerative changes. Cervical MRI reveale d a syrinx at the C1 level and a retro-odontoid soft tissue mass that sever ely compressed the spinal cord. The mass was of low signal intensity on bot h T1 and T2-weighted images. Conservative therapy could not stop the progre ssion of his symptoms, so posterior decompression via a laminectomy of C1 a nd occipitocervical fixation was performed. These procedures resulted in an improvement of his neurological condition and in reduction of the mass and the compression of the spinal cord. CONCLUSION The patient lacked any specific conditions that might have caused chronic a tlantoaxial subluxation. The degenerative changes alone might have provoked chronic atlantoaxial subluxation and a subsequent retro-odontoid soft tiss ue mass. In patients with this condition, posterior fixation without direct removal of the mass should be the first choice for surgical intervention. (C) 2001 by Elsevier Science Inc.