title: Ganglion cyst arising from the composite occipito-atlanto-axial joint cavity in a cat.
abstract: A four-year-old, female spayed Domestic Longhaired cat was referred for evaluation with a two month history of initial inability to jump progressing to ambulatory tetraparesis. Magnetic resonance imaging studies demonstrated a cystic lesion arising from the composite occipito-atlanto-axial joint cavity and extending to the region of the occipital bone and the axis. The lesion surrounded the spinal canal, causing moderate dorsal spinal cord compression at the atlanto-occipital joint. A dynamic myelographic study demonstrated attenuation of the dorsal contrast column at the atlanto-occipital joint when the cervical spine was positioned in extension. Partial excision of the cyst capsule by a ventral approach resulted in long-term (64 months) resolution of clinical signs. Histological evaluation was consistent with a ganglion cyst. An intra-spinal ganglion cyst arising from the composite occipito-atlanto-axial joint cavity may be considered as an uncommon differential diagnosis for cats with cervical myelopathy.
authors.affiliation: Takeshi Aikawa, BVSc, Diplomate JCVS, Aikawa Veterinary Medical Center, 4-3-1 Nishi Otiai, Shinjuku-ku, Tokyo 161-0031, Japan, Phone: + 81 3 5988 7887, Fax: + 81 3 5988 7887, E-mail: taikawa@wb3.so-net.ne.jp.
authors.forename: T
authors.initials: T
authors.lastname: Aikawa
authors.forename: S
authors.initials: S
authors.lastname: Sadahiro
authors.forename: M
authors.initials: M
authors.lastname: Nishimura
authors.forename: Y
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Shibata
mesh_terms: D000818:Animals; D001268:Atlanto-Axial Joint; D001269:Atlanto-Occipital Joint; D002371:Cat Diseases / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D002415:Cats; D005260:Female; D045888:Ganglion Cysts / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*
keywords: Ganglion cyst; cat; composite occipito-atlanto-axial joint; spine; synovial cyst