Journal of Clinical Neuroscience 20 (2013) 928–932
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Symptomatic facet cysts of the subaxial cervical spine Stylianos Pikis a, José E. Cohen a,b, Yair Barzilay c, Amir Hasharoni c, Leon Kaplan c, Eyal Itshayek a,⇑ a
Department of Neurosurgery, Hadassah–Hebrew University Medical Center, P.O. Box 12000, Jerusalem 91120, Israel Department of Radiology, Hadassah–Hebrew University Medical Center, Jerusalem, Israel c Department of Orthopedic Surgery, Hadassah–Hebrew University Medical Center, Jerusalem, Israel b
a r t i c l e
i n f o
Article history: Received 22 August 2012 Accepted 24 October 2012
Keywords: Cervical spine Facet cyst Ganglion cyst Subaxial Synovial cyst
a b s t r a c t Subaxial cervical facet cysts are uncommon. We report two patients with intraspinal, extradural, subaxial cervical spinal facet cysts, and review the literature to describe the epidemiology, clinical presentation, imaging ﬁndings, and treatment options for these lesions. Intraspinal, extradural, cervical spinal cysts should be considered as part of the differential diagnosis in patients presenting with clinical signs of cervical radiculopathy or myelopathy. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction With the widespread availability of imaging diagnostic modalities such as MRI and CT scans, reporting of spinal synovial cysts has been increasing; however, the etiology and natural history of these cysts remain unclear. Subaxial, cervical, synovial cysts most commonly occur at the C7 to T1 level, and typically present with pain, myelopathy, or radiculopathy. The literature includes only case reports and one series of 35 patients reported by Lyons et al.1 We could not identify any study evaluating outcomes following conservative treatment of this entity in the subaxial cervical spine. We describe two patients with subaxial cervical facet cysts presenting with radiculopathy, which had progressed to myelopathy in one patient, and review the relevant literature for this unusual condition. 2. Methods Relevant articles published from 1975 to March 2012 were identiﬁed using PubMed and Google Scholar. The search terms included cyst, subaxial, cervical, ganglion, synovial, intraspinal, extradural, facet joint, arthrography, epidemiology, pathophysiology, diagnosis, surgery, surgical outcome, and prognosis. Additional reports were identiﬁed through a review of citations in papers identiﬁed in the search.
⇑ Corresponding author. Tel.: +972 2 677 7092; fax: +972 2 643 1740. E-mail address: [email protected]
(E. Itshayek). 0967-5868/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jocn.2012.10.018
Clinical ﬁles and imaging data for two patients who presented with symptomatic subaxial cervical facet cysts were retrospectively reviewed. 3. Illustrative patients 3.1. Patient 1 A 71-year-old woman presented to the Spine Clinic with a 4 month history of neck pain radiating to the left hand. Numbness and paresthesia of the left hand were also reported. There was no history of trauma. Past medical history was signiﬁcant for hypertension and a transient ischemic attack (TIA). Neurological examination showed mild hypoesthesia over the left C7 dermatome, mild triceps weakness, and normal deep tendon reﬂexes. CT scan of the cervical spine revealed a partially calciﬁed epidural mass arising at the left facet joint of C6-7 (Fig. 1A). MRI of the cervical spine demonstrated an oval, peripherally enhancing epidural lesion in the posterolateral left aspect of the central canal at the C6-7 level with mild spinal cord compression (Fig. 1B,C). This was consistent with a synovial cyst arising from the left C6-7 facet joint. The patient was admitted for surgery. She underwent C6-7 left hemilaminectomy and microsurgical resection of the lesion, which originated from the left C6-7 facet joint and was adherent to the dura. The cyst consisted of a ﬁbrous-cartilaginous material and it was resected piecemeal. After excision, the nerve root was visualized from the axilla to the neural foramen. There were no surgical complications and the postoperative course was uneventful. The pa-
S. Pikis et al. / Journal of Clinical Neuroscience 20 (2013) 928–932
Fig. 1. (A) Axial CT scan in a 71-year-old woman with a 4 month history of neck pain radiating to the left hand demonstrates a partially calciﬁed extradural lesion arising at the left facet joint of C6-7. (B) Sagittal T1-weighted gadolinium-enhanced MRI reveals a peripherally enhancing mass located at the left lateral recess. (C) Sagittal T2-weighted MRI showing the partially calciﬁed extradural lesion.
tient experienced immediate pain relief. On histological examination, the lesion consisted of fragments of ﬁbrocartilage showing degenerative/regenerative changes, compatible with degenerative facet cyst. Five months after surgery, the radicular pain, hypoesthesia and weakness had resolved. There was no new neurological deﬁcit.
3.2. Patient 2 A 47-year-old woman was referred to our clinic for further evaluation and treatment of an epidural mass at C7-T1. The patient’s history was signiﬁcant for neck and interscapular pain of 1 year duration. Analgesics prescribed by her physician had failed to relieve the pain, which worsened with neck ﬂexion and extension, sometimes radiating to the right shoulder and to the right upper forearm. She also experienced an electrical sensation in the right axillary region. She had had increasing weakness and deterioration of the ﬁne motor skills of the upper limbs for the 3 months previous to her admission, which prevented her from carrying and from doing-up buttons on her clothing. She reported no gait or sphincter difﬁculties. Her neurological examination was signiﬁcant only for hyperreﬂexia, which was detected in all four limbs. Contrast-enhanced CT scan revealed a partially calciﬁed extradural lesion arising from the right facet joint of C7-T1 (Fig. 2A). Cervical spine MRI revealed an oval, peripherally enhancing 10.5 mm 6 mm extradural lesion in the posterior right aspect of the central canal at the C7-T1 level with moderate spinal cord compression and mild cord edema (Fig. 2B-E). This was consistent with a synovial cyst arising from the right C7-T1 facet joint. C7 laminectomy with complete cyst excision was performed. Using microsurgical techniques, the cyst was carefully dissected from the dura and excised en bloc. The cyst origin was found to be from the facet joint. There were no surgical complications, and the postoperative course was uneventful. The patient experienced immediate pain relief. Histological examination ﬁndings were consistent with a calciﬁed spinal synovial cyst.
At 2 year follow-up there was no evidence of recurrence and the patient had no residual neurological deﬁcit.
4. Literature review We identiﬁed and reviewed 26 publications, including 76 patients, with synovial and ganglion cysts of the subaxial cervical spine. We were able to extract data from 67 patients, including 30 from case reports or small series published since 1970, 35 patients described in a recent series from the Mayo Clinic,1 and two patients treated in our Medical Center. The mean age at presentation in the 67 patients was 68.2 years (range 3386 years) and there was a male preponderance (44 male, 23 female, 1.91:1). There were 38 cysts located at the cervicothoracic junction (56.7%),2–17 three cysts located at C6-7 (4.5%),18,19 ﬁve at C5-6 (7.5%),1,20,21 10 at C4-5 (14.9%),1,10,22 nine at C3-4 (13.4%),1,7,10,23,24 and two cysts located at C2-3 (3%).1 The most common presentation was radiculopathy in 35 patients (52.2%), followed by myelopathy in 30 (44.8%), Two patients presented with myeloradiculopathy (3.0%) (Table 1). The natural history of cervical synovial cysts is unpredictable. Among the reports in the literature, there was one MRIconﬁrmed spontaneous resolution of a synovial cyst located at C7-T1.5 Most patients experienced gradually progressive pain, myelopathy, or radiculopathy; however, rapid exacerbation of symptoms requiring immediate surgical treatment was reported in a few patients.11,12,21,22 Among 67 cases reviewed here, 65 patients underwent surgery (97.0%), one cyst was managed with CT-guided aspiration,19 and one cyst resolved 5 spontaneously. The surgical technique for the removal of synovial cysts typically consists of hemilaminectomy or laminectomy, with cyst excision. There was no report of patient death or cyst recurrence, or worsening of the preoperative symptoms following surgical intervention. All patients recovered at least partial function following surgery. Lyons et al.1 provided modiﬁed Rankin Scale (mRS) scores at long-term follow-up for 35 surgically treated patients: 12 patients scored 0 (asymptomatic); 17 achieved mRS score of
S. Pikis et al. / Journal of Clinical Neuroscience 20 (2013) 928–932
Fig. 2. (A) Axial contrast-enhanced CT scan of the cervical spine in a 47-year-old woman with chronic, intractable neck and interscapular pain of 1 year duration reveals a partially calciﬁed extradural lesion arising from the right facet joint of C7-T1. No enhancement is evident. (B) Axial T2-weighted MRI shows an extradural mass lesion compressing the posterolateral aspect of the cervical cord. (C) T1-weighted, (D) T1-weighted gadolinium-enhanced, and (E) T2-weighted sagittal MRI of the cervical spine show a peripherally enhancing partially cystic extradural lesion compressing the posterolateral aspect of the cord.
one (able to perform all usual activities despite some symptoms), four patients reached mRS score of two (slight disability), and two patients, who presented with signiﬁcant preoperative disability achieved a mRS score of three (moderate disability). The authors reported one postoperative infection treated successfully with surgical debridement and antibiotics. This was the only surgical complication reported in the literature. 5. Discussion Symptomatic intraspinal, extradural, subaxial facet cysts are unusual in the cervical and thoracic spine, although they are
relatively common in the lumbar spine.4 We report our experience with two patients who presented with synovial cysts at levels C6-7 and C7-T1, and review the literature. In 1974, Kao et al.18 introduced the term ‘‘juxtafacet cysts’’ to encompass both ganglion and synovial cysts. Since the term ‘‘juxtafacet’’ describes cysts originating from the periarticular tissue, and not from the joint itself, other authors later questioned the appropriateness of this term.4 Shima et al.14 proposed the term ‘‘degenerative intraspinal cyst’’ to describe cysts originating from degenerated spinal structures. Christophis et al. proposed the term ‘‘cystic formation of mobile spine’’ to describe cysts occurring in the mobile regions of the spine.4
Table 1 Reports of location, presentation and management of subaxial cervical facet cysts First authorRef.
Hatem10, McGuigan,22 Lyons1 20
Current Patient 1
Kotilainen,11 Cartwright,2 Cudlip,7 Stoodley,16 C7–T1 Hatem,10 Shima,14 Miwa,12 Cho,3 Gazzeri,9 Song,15 Colen,5 Christophis,4 Vastagh,17 Costa,6 Found,8 Seo,13 Current Patient 2 NA = not avaiable, M = male, F = female.
Gender No. Mean patients age (years) NA
Myelopathy 1 Radiculopathy 1 M1:F 3; NA 5 Myelopathy 7 Radiculopathy 1 Myeloradiculopathy 1 M2 Myelopathy 3 NA 8 Radiculopathy 7 M1:F 1 Myelopathy 1 NA 3 Radiculopathy 4 M1:F 2 Myelopathy 0 Radiculopathy 3 M15:F 6 Myelopathy 18 NA 17 Radiculopathy 19 Myeloradiculopathy 1
Surgery 2 Surgery 9
Surgery 10 Surgery 5 Surgery 2 CT-guided aspiration 1 Surgery 37 Spontaneous resolution 1
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5.1. Pathophysiology Spinal cysts occur in the mobile regions of the spine. Their exact etiology remains unclear. It is hypothesized that they are formed as a consequence of repeated microtrauma at areas of spinal instability. Synovial cysts are considered an extrusion of the synovial membrane through a capsular defect from a degenerated or unstable facet joint. Their walls consist of ﬁbrocollagenous tissue and have a synovial lining membrane,18 and they are in direct communication with the synovial cavity.24 In contrast, ganglion cysts contain a gelatinous material,18 are not in contact with the joint cavity,24 and on microscopic examination they do not have a synovial lining membrane.18,24 Presentation and management of synovial and ganglion cysts are the same. Typically these cystic lesions are unilateral, occurring dorsolateral to the spinal canal.15 However, a case of bilateral cysts11 and one instance of an interosseus cyst20 have been described.
Although facet cysts are considered by some to originate in a mildly unstable or at least hypermobile spinal segment, no author reported fusing the operated segments. All authors reported operating through laminectomy or hemilaminectomy. No recurrences were reported in follow-up periods averaging 35 months (range 0 to >70 months), based on data available for 57 patients. Kostanian et al.19 reported successful treatment of a C6-7 epidural cyst by aspiration under CT ﬂuoroscopic guidance. Aspiration was followed by injection of 6 mL of 0.25% bupivacaine with 80 mg of methylprednisone into the posterior epidural space. This therapeutic approach may be particularly useful for patients who would not tolerate operative management and for those who refuse surgery. The possibility of cyst recurrence, as well as the possible need for multiple procedures, should be explained to the patient. The literature is focused primarily on symptomatic lesions and does not include reports of asymptomatic lesions or patients who were managed conservatively; thus, data regarding the behavior of these lesions under observation is lacking. As a result, the natural history of synovial cysts in the cervical spine is not known.
5.2. Differential diagnosis The differential diagnoses of epidural cysts include detached disc fragments,3 arachnoid and perineural cyst,3,18,24 as well as dermoid cyst, meningioma, neuroﬁbroma, schwannoma, extradural metastasis,3,24 parasitic cyst,3 hypertrophic synovitis,3 and hypertrophic pigmented villonodular synovitis.3,24 The radiologic differential diagnosis should include neurinoma and epidural abscess.6 Tofuku et al.24 described differentiation between synovial and ganglion cysts by facet arthrography. 5.3. Diagnosis CT scans and MRI are the diagnostic imaging techniques of choice, with MRI the ﬁrst preference when available.2 MRI will demonstrate the nature of the cyst, as well as its relationship to the thecal sac. On MRI, synovial cysts appear as well-circumscribed, smooth, extradural lesions located adjacent to a facet joint. MRI demonstrates free ﬂuid within the cyst. The proteinaceous content of the cyst can demonstrate greater signal intensity than the surrounding cerebrospinal ﬂuid (CSF) on both T1-weighted and T2-weighted MRI. Calciﬁcation within the wall of the cyst produces low signal intensity on T1-weighted and T2-weighted images, while intracystal hemorrhage appears as higher intensity than CSF.25 CT scans may demonstrate free gas within the cyst, suggesting communication of the cyst with a facet joint or a degenerated disc space.25 5.4. Treatment The natural history of epidural cysts remains unclear. In patients presenting with small, asymptomatic or mildly symptomatic cysts, conservative treatment is advised.6,24 In patients where communication of the cyst with the facet joint is conﬁrmed, corticosteroid injections within the facet joint have been suggested. While steroids may provide some pain relief, there is no evidence of other beneﬁts.24 Please rewrite sentence as follows: Surgical treatment with complete resection of the cyst must be considered when there is rapid deterioration and in the presence of severe pain that is not responsive to medical management,6 as well as in cases of progressive radicular weakness or myelopathy.24 With the exception of two patients,5,19 all patients reported were managed with surgical excision of the cyst. Most reports of symptomatic synovial cyst in the lumbar spine were also managed surgically.4
6. Conclusion Intraspinal, extradural, subaxial, cervical faces cysts are rarely occuring lesions with a poorly understood natural history. They may be symptomatic or asymptomatic. If symptomatic, they present with radiculopathy or myelopathy, which is clinically indistinguishable from disk herniation or spinal canal stenosis. The diagnosis is best established by contrast-enhanced MRI, in which a peripherally enhancing cystic lesion is seen. In mildly symptomatic patients, treatment is initially conservative. Surgical management involves excision of the cyst through laminectomy without fusion and offers excellent results. CT-guided aspiration of the cyst may be an alternative approach in patients when symptoms are severe, in those with rapid clinical deterioration, in those who are poor surgical candidates and in those who refuse surgery. References 1. Lyons MK, Birch BD, Krauss WE, et al. Subaxial cervical synovial cysts: report of 35 histologically conﬁrmed surgically treated cases and review of the literature. Spine (Phila Pa 1976) 2011;36:E1285–9. 2. Cartwright MJ, Nehls DG, Carrion CA, et al. Synovial cyst of a cervical facet joint: case report. Neurosurgery 1985;16:850–2. 3. Cho BY, Zhang HY, Kim HS. Synovial cyst in the cervical region causing severe myelopathy. Yonsei Med J 2004;45:539–42. 4. Christophis P, Asamoto S, Kuchelmeister K, et al. ‘‘Juxtafacet cysts’’, a misleading name for cystic formations of mobile spine (CYFMOS). Eur Spine J 2007;16:1499–505. 5. Colen CB, Rengachary S. Spontaneous resolution of a cervical synovial cyst. Case illustration. J Neurosurg Spine 2006;4:186. 6. Costa F, Menghetti C, Cardia A, et al. Cervical synovial cyst: case report and review of literature. Eur Spine J 2010;19(Suppl. 2):S100–2. 7. Cudlip S, Johnston F, Marsh H. Subaxial cervical synovial cyst presenting with myelopathy. Report of three cases. J Neurosurg 1999;90:141–4. 8. Found E, Bewyer D. Cervical synovial cyst: case report. Iowa Orthop J 2011; 31:215–8. 9. Gazzeri R, Galarza M, Gorgoglione L, et al. Cervical cyst of the ligamentum ﬂavum and C7–T1 subluxation: case report. Eur Spine J 2005;14:807–9. 10. Hatem O, Bedou G, Negre C, et al. Intraspinal cervical degenerative cyst. Report of three cases. J Neurosurg 2001;95:139–42. 11. Kotilainen E, Marttila RJ. Paraparesis caused by a bilateral cervical synovial cyst. Acta Neurol Scand 1997;96:59–61. 12. Miwa M, Doita M, Takayama H, et al. An expanding cervical synovial cyst causing acute cervical radiculopathy. J Spinal Disord Tech 2004;17:331–3. 13. Seo HY, Chung JY, Park GH, et al. Cervical facet cyst causing progressive paraplegia: a case report. J Korean Soc Spine Surg 2011;18:19–33. 14. Shima Y, Rothman SL, Yasura K, et al. Degenerative intraspinal cyst of the cervical spine: case report and literature review. Spine (Phila Pa 1976) 2002;27: E18–22. 15. Song JK, Musleh W, Christie SD, et al. Cervical juxtafacet cysts: case report and literature review. Spine J 2006;6:279–81. 16. Stoodley MA, Jones NR, Scott G. Cervical and thoracic juxtafacet cysts causing neurologic deﬁcits. Spine (Phila Pa 1976) 2000;25:970–3.
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17. Vastagh I, Palasti A, Nagy H, et al. Cervical juxtafacet cyst combined with spinal dysraphism. Clin Imaging 2008;32:387–9. 18. Kao CC, Winkler SS, Turner JH. Synovial cyst of spinal facet. Case report. J Neurosurg 1974;41:372–6. 19. Kostanian VJ, Mathews MS. CT guided aspiration of a cervical synovial cyst. Case report and technical note. Interv Neuroradiol 2007;13:295–8. 20. Jost SC, Hsien Tu P, Wright NM. Symptomatic intraosseous synovial cyst in the cervical spine: a case report. Spine (Phila Pa 1976) 2003;28:E344–6. 21. Moon HJ, Kim JH, Kim JH, et al. Cervical juxtafacet cyst with myelopathy due to postoperative instability. Case report. Neurol Med Chir (Tokyo) 2010;50: 1129–31.
22. McGuigan C, Stevens J, Gabriel CM. A synovial cyst in the cervical spine causing acute spinal cord compression. Neurology 2005;65:1293. 23. Brotis AG, Kapsalaki EZ, Papadopoulos EK, et al. A cervical ligamentum ﬂavum cyst in an 82-year-old woman presenting with spinal cord compression: a case report and review of the literature. J Med Case Rep 2012;6:92. 24. Tofuku K, Koga H, Komiya S. Facet arthrography of a cervical synovial cyst. J Neurointerv Surg 2012;4:e17. 25. Khan AM, Girardi F. Spinal lumbar synovial cysts. Diagnosis and management challenge. Eur Spine J 2006;15:1176–82.