Skeletal Radiol DOI 10.1007/s00256-014-1974-7
CASE REPORT
Solitary C1 spinal osteochondroma causing vertebral artery compression and acute cerebellar infarct Yaxia Zhang & Hakan Ilaslan & Muhammad S. Hussain & Mark Bain & Thomas W. Bauer
Received: 19 March 2014 / Revised: 24 July 2014 / Accepted: 28 July 2014 # ISS 2014
Abstract Osteochondroma is a common benign bone lesion, usually involving the long bones. Spinal involvement is rare. The clinical presentation of spinal osteochondroma varies according to the site of the lesion. The most common reported clinical presentation is secondary to encroachment of the lesion on the spinal canal or nerve roots. Less common presentations such as a palpable neck mass, dysphagia, sleep apnea, paralysis of left vocal cord or acute respiratory distress have been reported when the lesions compress the anatomic structures anteriorly. We describe a rare case of a young patient who presented with an emergent critical condition of acute cerebellar infarct as a result of vertebral artery compression caused by a solitary C1 spinal osteochondroma. Keywords Spinal osteochondroma . Solitary . Vertebral artery compression . Acute cerebellar infarct
Introduction Osteochondroma is a common benign bone lesion, which accounts for approximately 30.6–35 % of benign bone tumors and tumor-like lesions [1, 2]. It is composed of a cartilaginous cap and underlying bony stalk that arise from the external Y. Zhang (*) : T. W. Bauer Department of Pathology, Cleveland Clinic, Cleveland, OH, USA e-mail: [email protected] H. Ilaslan The Imaging Institute, Cleveland Clinic, Cleveland, OH, USA M. S. Hussain : M. Bain The Cerebrovascular Center, Cleveland Clinic, Cleveland, OH, USA T. W. Bauer The Department of Orthopaedic Surgery and The Spine Center, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
surface of the bone, with its marrow continuous with that of the underlying bone [3]. It can occur as a solitary lesion or as multiple lesions in an autosomal dominant syndrome of hereditary multiple osteochondromas. Osteochondroma has a predilection to occur on the surface of the metaphyses of long tubular bones, and the knee is the most frequent location. Only about 1–4 % of solitary osteochondromas and up to 7–9 % of multiple osteochondromas affect the spine [4, 5]. While the majority of spinal osteochondromas are asymptomatic, patients may present with a variety of clinical manifestations depending on the tumor location. In up to 40 % of cases, patients with spinal involvement have presented with symptoms related to spinal cord compression due to encroachment of the lesion on the spinal canal or nerve roots [4, 6, 7]. Other symptoms, such as dysphagia, hoarseness, Horner’s syndrome, paralysis of the vocal cords or acute onset of respiratory distress, have been described when the lesion extends anteriorly [8–10]. As far as we know, there have been only three previous reports of an osteochondroma extending laterally and blocking the vertebral artery [11–13]. We describe an unusual case in a young patient who presented with symptoms of an acute cerebellar infarct due to vertebral artery compromise secondary to a solitary spinal osteochondroma of the C1 vertebra. Imaging was required to localize the lesion and demonstrate vascular compromise, but final diagnosis required histopathological evaluation. Surgical excision was curative. The patient gave informed consent to submit this case report for publication. Case report A 19-year-old female presented with a 2-day history of vertigo, nausea, vomiting and headache. She felt loss of balance in the last few days and had a sensation of right sided “heaviness.” She denied any falls or loss of consciousness. There were no changes in vision, weakness, paresthesias or seizures,
Skeletal Radiol
and she denied any head injury. She went to the emergency department, where computed tomography image of the brain showed a 20 × 17-mm hypodense lesion in the left cerebellum. Magnetic resonance imaging/angiogram (MRI/MRA) of the brain was performed for further characterization, which showed multiple confluent and nodular acute embolic infarcts involving the left cerebellum within the left posterior inferior cerebellar artery (PICA) distribution (Fig. 1a). In addition, MRI demonstrated a well-defined osseous excrescence arising from the lateral mass of the C1 vertebra, displacing the left distal V2 segment of the left vertebral artery laterally and significantly diminishing flow-related enhancement within the distal horizontal segment (Fig. 1b-c). The CT angiogram confirmed the lesion to have corticomedullary continuity with the lateral mass of C1 and mass effect on the adjacent left vertebral artery, displacing it and narrowing the V2 segment 50 % (Fig. 1d). Digital subtraction angiography (DSA) Fig. 1 a T2-weighted axial MR image of the posterior fossa shows a hyperintense area in the left cerebellum (arrowheads), which showed restricted diffusion consistent with acute infarction. b Coronal T1-weighted image of the brain demonstrates an oval, well-circumscribed mass of the C1 vertebra laterally (arrows) with corticomedullary continuity typical of an osteochondroma. c Multi-slab 3D time-of-flight MR angiographic image shows marked loss of flow-related signal in the distal horizontal portion of the left vertebral artery V3 segment. d Coronal reconstructed image of the CT angiogram shows a pedunculated ossified mass (arrows), which is consistent with an osteochondroma. e Digital subtraction angiography (DSA) during injection of the left vertebral artery shows a focal area of 50 % narrowing at the distal left V2 segments (arrows)
examination of the internal carotid and vertebral arteries again revealed stenosis of the distal left V2 segments of the left vertebral artery (Fig. 1e), which was improved when the head turned to the right and worsened when the head turned to the left with flow limitation. The patient underwent excision of the cervical bone mass for decompression of the vertebral artery. Grossly, the resected mass was 1.7 cm in the greatest dimension, irregular and had a thin gray-white cartilaginous cap. Microscopically, the lesion was composed of a 1-mm-thick hyaline cartilage cap and underlying cancellous bone (Fig. 2a). The chondrocytes demonstrated minimal cytological atypia and architecturally recapitulated the zones of a growth plate (Fig. 2b). The cartilage appeared to be undergoing endochondral ossification, and the core of the bony stalk was continuous with the cancellous bone of the underlying medullary cavity. These findings are diagnostic of an osteochondroma.
Skeletal Radiol
Fig. 2 a The lesion is composed of a thin cartilage cap (C) that has undergone endochondral ossification. The core of the osteochondroma stalk (S) is continuous with the underlying medullary cavity. These features are typical of an osteochondroma. b The chondrocytes in the cartilage cap demonstrate minimal cytological atypia and architecturally recapitulate the zones of a growth plate
Post-operation angiography confirmed the patency of the left vertebral artery with no residual stenosis, even when the head turned to either side. Her pain was significantly improved immediately after the operation, and she was able to ambulate. At the last follow-up 6 months after surgery, she was asymptomatic without any headache, weakness, numbness, visual changes, unsteadiness of gait or visual disturbance, and she had an entirely normal neurological exam.
Discussion Osteochondroma is among the most common benign bone lesions and has traditionally been classified as a developmental or hamartomatous disorder. It was hypothesized that osteochondroma formed as a result of aberrant epiphyseal development with displacement of physial cartilage through the perichondrial fibrous ring and subsequent growth at right angles to the long axis of the bone [1]. The most significant recent development suggests that it is a neoplastic condition due to clonal aberrations related to the mutations of EXT
tumor suppressor genes [14], although the mechanism by which EXT mutations contribute to the pathogenesis of osteochondroma remains unclear. Solitary spinal osteochondroma is quite rare in the reported series [15]. However, its actual incidence may be underestimated since the majority of the patients with spinal osteochondroma are asymptomatic. Gille et al. [4] reviewed the English literature up to 2003 and found 156 cases of spinal involvement. Our recent literature search identified an additional 69 cases of solitary spinal osteochondroma reported from 2004 to 2014 [12, 16–22]. According to Albrecht et al. [15], the average age of patients presenting with the tumor is 30 years with a male predominance ratio of 2.5:1. It is often located in the cervical (up to 50 %) and upper thoracic spine, whereas the inferior thoracic, lumbar and sacral levels are rarely involved [16]. It often arises in the posterior arch, but can also develop in the vertebral body, a pedicle, spina bifida occulta [23] or the articular facet [12]. The clinical presentation varies based on the tumor location. Up to 30 to 40 % of patients have presented with symptoms such as myelopathy or quadriparesis related to spinal cord compression [4, 24]. Rarely, spinal osteochondroma may extend anteriorly and cause symptoms such as dysphagia, hoarseness, “globus symptoms,” Horner’s syndrome or acute onset of respiratory failure [8–10, 25] when the mass compresses the surrounding anatomic structures such as the upper respiratory tract or recurrent laryngeal nerve. As far as we know, there have only been three previous reports of an osteochondroma of the spine causing occlusion of the vertebral artery [11–13]. In the first case [11], the patient had a diagnosis of multiple hereditary osteochondromas. The C1 spinal osteochondroma arising from the vertebra caused occlusion of the right vertebral artery, and the patient presented with symptoms of cerebral ischemia. The spinal osteochondroma was not resected since the artery was already completely occluded and symptoms were not progressive. In the second reported case [12], the patient presented with radiating neck pain with progressive ascending weakness of both lower limbs of 2 months’ duration and later on with progressive weakness of both upper limbs. Imaging showed an expansile tumor on the left side of C3–5 involving the transverse processes, lamina and pedicles; vertebral angiography demonstrated complete blockage of the left vertebral artery. The lesion was removed by multiple operations, and the patient recovered completely without any deficits at 1-year follow-up. Histological images did show some cartilage and bone formation even though the classic microscopic findings of osteochondroma were not entirely demonstrated because of the multiple operations. In the third case [13], the patient had C2 neuralgia and complete occlusion of vertebral artery due to a C2 osteochondroma arising from the transverse process. Complete surgical resection was the treatment modality.
Skeletal Radiol
To the best of our knowledge, this is the first report of a histologically proven solitary osteochondroma of the C1 vertebra with acute cerebellar infarct. Presumably, compression of the vertebral artery by the osteochondroma caused stretching of the vessel, damage to the intima and media, reduced blood flow with platelet aggregation, subsequent thrombosis, followed by embolization to the PICA [26, 27]. The CT angiogram in our case was performed to demonstrate the degree of vascular compromise and the relationship to adjacent bony structures. Digital subtraction angiography dynamically evaluated vascular compression with head motion. Although not initially recognized in our case, corticomedullary continuity on imaging studies can help distinguish an osteochondroma from congenital variation of the spine anatomy in this location. Complete surgical resection of the osteochondroma with decompression of the vertebral artery provided successful treatment in our case. In conclusion, we present an extremely unusual clinical presentation in which solitary spinal osteochondroma induced vascular compromise and cerebellar ischemia. Imaging localized the lesion, but histological evaluation was necessary for final diagnosis. Surgical excision was curative. Acknowledgment Funding There was no funding for this case report. Disclosure The authors declare that they have no conflict of interest.
References 1. Dorfman HD, Czerniak B. Bone Tumors. 1998. 2. Unni KK, Inwards CY. Dahlin’s Bone Tumors: General Aspects and Data on 10,165 cases. 6th ed. Philadelphia: Lippincott Williams & Wilkins Publishers; 2010. 3. Fletcher CDM, Bridge JA, Hogendoorn PCW, Mertens F. WHO Classification of Tumours of Soft Tissue and Bone. 2013 4. Gille O, Pointillart V, Vital JM. Course of spinal solitary osteochondromas. Spine. 2005;30(1):E13–9. 5. Solomon L. Hereditary multiple exostosis. J Bone Joint Surg (Br). 1963;45:292–304. 6. Song KJ, Lee KB. Solitary osteochondroma of the thoracic spine causing myelopathy. European journal of pediatric surgery. 2007; 17(3):210–13. 7. Sharma MC, Arora R, Deol PS, Mahapatra AK, Mehta VS, Sarkar C. Osteochondroma of the spine: an enigmatic tumor of the spinal cord. A series of 10 cases. J Neurosurg Sci. 2002;46(2):66–70. 8. Wang V, Chou D. Anterior C1-2 osteochondroma presenting with dysphagia and sleep apnea. J Clin Neurosci: Off J Neurosurg Soc Australas. 2009;16(4):581–82.
9. Zhao CQ, Jiang SD, Jiang LS, Dai LY. Horner Syndrome due to a solitary osteochondroma of C7: a case report and review of the literature. Spine. 2007;32(16):E471–74. 10. Certo F, Sciacca G, Caltabiano R, et al. Anterior, extracanalar, cervical spine osteochondroma associated with DISH: description of a very rare tumor causing bilateral vocal cord paralysis, laryngeal compression and dysphagia. Case Repo Rev Lit Eur Rev Med Pharmacol Sci. 2014;18(1 Suppl):34–40. 11. Altaf F, Movlik H, Brew S, Rezajooi K, Casey A. Osteochondroma of C1 causing vertebral artery occlusion. Br J Neurosurg. 2013;27(1): 130–31. 12. Srikantha U, Bhagavatula ID, Satyanarayana S, Somanna S, Chandramouli BA. Spinal osteochondroma: spectrum of a rare disease. J Neurosurg Spine. 2008;8(6):561–66. 13. George B, Atallah A, Laurian C, Tayon B, Mikol J. Cervical osteochondroma (C2 level) with vertebral artery occlusion and second cervical nerve root irritation. Surg Neurol. 1989;31(6):459–64. 14. Garcia RA, Inwards CY, Unni KK. Benign bone tumors—recent developments. Semin Diagn Pathol. 2011;28(1):73–85. 15. Albrecht S, Crutchfield JS, SeGall GK. On spinal osteochondromas. J Neurosurg. 1992;77(2):247–52. 16. Kuraishi K, Hanakita J, Takahashi T, Watanabe M, Honda F. Symptomatic osteochondroma of lumbosacral spine: report of 5 cases. Neurol Med Chir. 2013;38(12):2381-386 17. Mardi K, Madan S. Pediatric solitary osteochondroma of T1 vertebra causing spinal cord compression: a case report. S Asian J Cancer. 2013;2(3):144. 18. Mehrian P, Karimi MA, Kahkuee S, Bakhshayeshkaram M, Ghasemikhah R. Solitary osteochondroma of the thoracic spine with compressive myelopathy; a rare presentation. Iran J Radiol: Radiol J Published Iran Radiol Soc. 2013;10(2):77–80. 19. Natale M, Rotondo M, D’Avanzo R, Scuotto A. Solitary lumbar osteochondroma presenting with spinal cord compression. BMJ case reports. 2013; 2013 20. Schomacher M, Suess O, Kombos T. Osteochondromas of the cervical spine in atypical location. Acta Neurochir. 2009;151(6):629–33. discussion 633. 21. Sekharappa V, Amritanand R, Krishnan V, David KS. Symptomatic solitary osteochondroma of the subaxial cervical spine in a 52-yearold patient. Asian Spine J. 2014;8(1):84–8. 22. Ogul H, Tuncer K, Can CE, Kantarci M. An unusual cause of spinal compression in a young woman: cervical osteochondroma. Spine J. 2014; 14(7):1356. 23. Ofluoglu AE, Abdallah A, Gokcedag A. Solitary osteochondroma arising from cervical spina bifida occulta. Case Rep Orthop. 2013;2013:509745. 24. Er U, Simsek S, Yigitkanli K, Adabag A, Kars HZ. Myelopathy and quadriparesis due to spinal cord compression of C1 laminar osteochondroma. Asian Spine J. 2012;6(1):66–70. 25. Wong K, Bhagat S, Clibbon J, Rai AS. “Globus symptoms”: a rare case of giant osteochondroma of the axis treated with high cervical extrapharyngeal approach. Glob Spine J. 2013;3(2):115–18. 26. Miyachi S, Okamura K, Watanabe M, Inoue N, Nagatani T, Takagi T. Cerebellar stroke due to vertebral artery occlusion after cervical spine trauma. Two Case Rep Spine. 1994;19(1):83–8. 27. Muratsu H, Doita M, Yanagi T, et al. Cerebellar infarction resulting from vertebral artery occlusion associated with a Jefferson fracture. J Spinal Disord Tech. 2005;18(3):293–96.
CASE REPORT
Solitary C1 spinal osteochondroma causing vertebral artery compression and acute cerebellar infarct Yaxia Zhang & Hakan Ilaslan & Muhammad S. Hussain & Mark Bain & Thomas W. Bauer
Received: 19 March 2014 / Revised: 24 July 2014 / Accepted: 28 July 2014 # ISS 2014
Abstract Osteochondroma is a common benign bone lesion, usually involving the long bones. Spinal involvement is rare. The clinical presentation of spinal osteochondroma varies according to the site of the lesion. The most common reported clinical presentation is secondary to encroachment of the lesion on the spinal canal or nerve roots. Less common presentations such as a palpable neck mass, dysphagia, sleep apnea, paralysis of left vocal cord or acute respiratory distress have been reported when the lesions compress the anatomic structures anteriorly. We describe a rare case of a young patient who presented with an emergent critical condition of acute cerebellar infarct as a result of vertebral artery compression caused by a solitary C1 spinal osteochondroma. Keywords Spinal osteochondroma . Solitary . Vertebral artery compression . Acute cerebellar infarct
Introduction Osteochondroma is a common benign bone lesion, which accounts for approximately 30.6–35 % of benign bone tumors and tumor-like lesions [1, 2]. It is composed of a cartilaginous cap and underlying bony stalk that arise from the external Y. Zhang (*) : T. W. Bauer Department of Pathology, Cleveland Clinic, Cleveland, OH, USA e-mail: [email protected] H. Ilaslan The Imaging Institute, Cleveland Clinic, Cleveland, OH, USA M. S. Hussain : M. Bain The Cerebrovascular Center, Cleveland Clinic, Cleveland, OH, USA T. W. Bauer The Department of Orthopaedic Surgery and The Spine Center, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
surface of the bone, with its marrow continuous with that of the underlying bone [3]. It can occur as a solitary lesion or as multiple lesions in an autosomal dominant syndrome of hereditary multiple osteochondromas. Osteochondroma has a predilection to occur on the surface of the metaphyses of long tubular bones, and the knee is the most frequent location. Only about 1–4 % of solitary osteochondromas and up to 7–9 % of multiple osteochondromas affect the spine [4, 5]. While the majority of spinal osteochondromas are asymptomatic, patients may present with a variety of clinical manifestations depending on the tumor location. In up to 40 % of cases, patients with spinal involvement have presented with symptoms related to spinal cord compression due to encroachment of the lesion on the spinal canal or nerve roots [4, 6, 7]. Other symptoms, such as dysphagia, hoarseness, Horner’s syndrome, paralysis of the vocal cords or acute onset of respiratory distress, have been described when the lesion extends anteriorly [8–10]. As far as we know, there have been only three previous reports of an osteochondroma extending laterally and blocking the vertebral artery [11–13]. We describe an unusual case in a young patient who presented with symptoms of an acute cerebellar infarct due to vertebral artery compromise secondary to a solitary spinal osteochondroma of the C1 vertebra. Imaging was required to localize the lesion and demonstrate vascular compromise, but final diagnosis required histopathological evaluation. Surgical excision was curative. The patient gave informed consent to submit this case report for publication. Case report A 19-year-old female presented with a 2-day history of vertigo, nausea, vomiting and headache. She felt loss of balance in the last few days and had a sensation of right sided “heaviness.” She denied any falls or loss of consciousness. There were no changes in vision, weakness, paresthesias or seizures,
Skeletal Radiol
and she denied any head injury. She went to the emergency department, where computed tomography image of the brain showed a 20 × 17-mm hypodense lesion in the left cerebellum. Magnetic resonance imaging/angiogram (MRI/MRA) of the brain was performed for further characterization, which showed multiple confluent and nodular acute embolic infarcts involving the left cerebellum within the left posterior inferior cerebellar artery (PICA) distribution (Fig. 1a). In addition, MRI demonstrated a well-defined osseous excrescence arising from the lateral mass of the C1 vertebra, displacing the left distal V2 segment of the left vertebral artery laterally and significantly diminishing flow-related enhancement within the distal horizontal segment (Fig. 1b-c). The CT angiogram confirmed the lesion to have corticomedullary continuity with the lateral mass of C1 and mass effect on the adjacent left vertebral artery, displacing it and narrowing the V2 segment 50 % (Fig. 1d). Digital subtraction angiography (DSA) Fig. 1 a T2-weighted axial MR image of the posterior fossa shows a hyperintense area in the left cerebellum (arrowheads), which showed restricted diffusion consistent with acute infarction. b Coronal T1-weighted image of the brain demonstrates an oval, well-circumscribed mass of the C1 vertebra laterally (arrows) with corticomedullary continuity typical of an osteochondroma. c Multi-slab 3D time-of-flight MR angiographic image shows marked loss of flow-related signal in the distal horizontal portion of the left vertebral artery V3 segment. d Coronal reconstructed image of the CT angiogram shows a pedunculated ossified mass (arrows), which is consistent with an osteochondroma. e Digital subtraction angiography (DSA) during injection of the left vertebral artery shows a focal area of 50 % narrowing at the distal left V2 segments (arrows)
examination of the internal carotid and vertebral arteries again revealed stenosis of the distal left V2 segments of the left vertebral artery (Fig. 1e), which was improved when the head turned to the right and worsened when the head turned to the left with flow limitation. The patient underwent excision of the cervical bone mass for decompression of the vertebral artery. Grossly, the resected mass was 1.7 cm in the greatest dimension, irregular and had a thin gray-white cartilaginous cap. Microscopically, the lesion was composed of a 1-mm-thick hyaline cartilage cap and underlying cancellous bone (Fig. 2a). The chondrocytes demonstrated minimal cytological atypia and architecturally recapitulated the zones of a growth plate (Fig. 2b). The cartilage appeared to be undergoing endochondral ossification, and the core of the bony stalk was continuous with the cancellous bone of the underlying medullary cavity. These findings are diagnostic of an osteochondroma.
Skeletal Radiol
Fig. 2 a The lesion is composed of a thin cartilage cap (C) that has undergone endochondral ossification. The core of the osteochondroma stalk (S) is continuous with the underlying medullary cavity. These features are typical of an osteochondroma. b The chondrocytes in the cartilage cap demonstrate minimal cytological atypia and architecturally recapitulate the zones of a growth plate
Post-operation angiography confirmed the patency of the left vertebral artery with no residual stenosis, even when the head turned to either side. Her pain was significantly improved immediately after the operation, and she was able to ambulate. At the last follow-up 6 months after surgery, she was asymptomatic without any headache, weakness, numbness, visual changes, unsteadiness of gait or visual disturbance, and she had an entirely normal neurological exam.
Discussion Osteochondroma is among the most common benign bone lesions and has traditionally been classified as a developmental or hamartomatous disorder. It was hypothesized that osteochondroma formed as a result of aberrant epiphyseal development with displacement of physial cartilage through the perichondrial fibrous ring and subsequent growth at right angles to the long axis of the bone [1]. The most significant recent development suggests that it is a neoplastic condition due to clonal aberrations related to the mutations of EXT
tumor suppressor genes [14], although the mechanism by which EXT mutations contribute to the pathogenesis of osteochondroma remains unclear. Solitary spinal osteochondroma is quite rare in the reported series [15]. However, its actual incidence may be underestimated since the majority of the patients with spinal osteochondroma are asymptomatic. Gille et al. [4] reviewed the English literature up to 2003 and found 156 cases of spinal involvement. Our recent literature search identified an additional 69 cases of solitary spinal osteochondroma reported from 2004 to 2014 [12, 16–22]. According to Albrecht et al. [15], the average age of patients presenting with the tumor is 30 years with a male predominance ratio of 2.5:1. It is often located in the cervical (up to 50 %) and upper thoracic spine, whereas the inferior thoracic, lumbar and sacral levels are rarely involved [16]. It often arises in the posterior arch, but can also develop in the vertebral body, a pedicle, spina bifida occulta [23] or the articular facet [12]. The clinical presentation varies based on the tumor location. Up to 30 to 40 % of patients have presented with symptoms such as myelopathy or quadriparesis related to spinal cord compression [4, 24]. Rarely, spinal osteochondroma may extend anteriorly and cause symptoms such as dysphagia, hoarseness, “globus symptoms,” Horner’s syndrome or acute onset of respiratory failure [8–10, 25] when the mass compresses the surrounding anatomic structures such as the upper respiratory tract or recurrent laryngeal nerve. As far as we know, there have only been three previous reports of an osteochondroma of the spine causing occlusion of the vertebral artery [11–13]. In the first case [11], the patient had a diagnosis of multiple hereditary osteochondromas. The C1 spinal osteochondroma arising from the vertebra caused occlusion of the right vertebral artery, and the patient presented with symptoms of cerebral ischemia. The spinal osteochondroma was not resected since the artery was already completely occluded and symptoms were not progressive. In the second reported case [12], the patient presented with radiating neck pain with progressive ascending weakness of both lower limbs of 2 months’ duration and later on with progressive weakness of both upper limbs. Imaging showed an expansile tumor on the left side of C3–5 involving the transverse processes, lamina and pedicles; vertebral angiography demonstrated complete blockage of the left vertebral artery. The lesion was removed by multiple operations, and the patient recovered completely without any deficits at 1-year follow-up. Histological images did show some cartilage and bone formation even though the classic microscopic findings of osteochondroma were not entirely demonstrated because of the multiple operations. In the third case [13], the patient had C2 neuralgia and complete occlusion of vertebral artery due to a C2 osteochondroma arising from the transverse process. Complete surgical resection was the treatment modality.
Skeletal Radiol
To the best of our knowledge, this is the first report of a histologically proven solitary osteochondroma of the C1 vertebra with acute cerebellar infarct. Presumably, compression of the vertebral artery by the osteochondroma caused stretching of the vessel, damage to the intima and media, reduced blood flow with platelet aggregation, subsequent thrombosis, followed by embolization to the PICA [26, 27]. The CT angiogram in our case was performed to demonstrate the degree of vascular compromise and the relationship to adjacent bony structures. Digital subtraction angiography dynamically evaluated vascular compression with head motion. Although not initially recognized in our case, corticomedullary continuity on imaging studies can help distinguish an osteochondroma from congenital variation of the spine anatomy in this location. Complete surgical resection of the osteochondroma with decompression of the vertebral artery provided successful treatment in our case. In conclusion, we present an extremely unusual clinical presentation in which solitary spinal osteochondroma induced vascular compromise and cerebellar ischemia. Imaging localized the lesion, but histological evaluation was necessary for final diagnosis. Surgical excision was curative. Acknowledgment Funding There was no funding for this case report. Disclosure The authors declare that they have no conflict of interest.
References 1. Dorfman HD, Czerniak B. Bone Tumors. 1998. 2. Unni KK, Inwards CY. Dahlin’s Bone Tumors: General Aspects and Data on 10,165 cases. 6th ed. Philadelphia: Lippincott Williams & Wilkins Publishers; 2010. 3. Fletcher CDM, Bridge JA, Hogendoorn PCW, Mertens F. WHO Classification of Tumours of Soft Tissue and Bone. 2013 4. Gille O, Pointillart V, Vital JM. Course of spinal solitary osteochondromas. Spine. 2005;30(1):E13–9. 5. Solomon L. Hereditary multiple exostosis. J Bone Joint Surg (Br). 1963;45:292–304. 6. Song KJ, Lee KB. Solitary osteochondroma of the thoracic spine causing myelopathy. European journal of pediatric surgery. 2007; 17(3):210–13. 7. Sharma MC, Arora R, Deol PS, Mahapatra AK, Mehta VS, Sarkar C. Osteochondroma of the spine: an enigmatic tumor of the spinal cord. A series of 10 cases. J Neurosurg Sci. 2002;46(2):66–70. 8. Wang V, Chou D. Anterior C1-2 osteochondroma presenting with dysphagia and sleep apnea. J Clin Neurosci: Off J Neurosurg Soc Australas. 2009;16(4):581–82.
9. Zhao CQ, Jiang SD, Jiang LS, Dai LY. Horner Syndrome due to a solitary osteochondroma of C7: a case report and review of the literature. Spine. 2007;32(16):E471–74. 10. Certo F, Sciacca G, Caltabiano R, et al. Anterior, extracanalar, cervical spine osteochondroma associated with DISH: description of a very rare tumor causing bilateral vocal cord paralysis, laryngeal compression and dysphagia. Case Repo Rev Lit Eur Rev Med Pharmacol Sci. 2014;18(1 Suppl):34–40. 11. Altaf F, Movlik H, Brew S, Rezajooi K, Casey A. Osteochondroma of C1 causing vertebral artery occlusion. Br J Neurosurg. 2013;27(1): 130–31. 12. Srikantha U, Bhagavatula ID, Satyanarayana S, Somanna S, Chandramouli BA. Spinal osteochondroma: spectrum of a rare disease. J Neurosurg Spine. 2008;8(6):561–66. 13. George B, Atallah A, Laurian C, Tayon B, Mikol J. Cervical osteochondroma (C2 level) with vertebral artery occlusion and second cervical nerve root irritation. Surg Neurol. 1989;31(6):459–64. 14. Garcia RA, Inwards CY, Unni KK. Benign bone tumors—recent developments. Semin Diagn Pathol. 2011;28(1):73–85. 15. Albrecht S, Crutchfield JS, SeGall GK. On spinal osteochondromas. J Neurosurg. 1992;77(2):247–52. 16. Kuraishi K, Hanakita J, Takahashi T, Watanabe M, Honda F. Symptomatic osteochondroma of lumbosacral spine: report of 5 cases. Neurol Med Chir. 2013;38(12):2381-386 17. Mardi K, Madan S. Pediatric solitary osteochondroma of T1 vertebra causing spinal cord compression: a case report. S Asian J Cancer. 2013;2(3):144. 18. Mehrian P, Karimi MA, Kahkuee S, Bakhshayeshkaram M, Ghasemikhah R. Solitary osteochondroma of the thoracic spine with compressive myelopathy; a rare presentation. Iran J Radiol: Radiol J Published Iran Radiol Soc. 2013;10(2):77–80. 19. Natale M, Rotondo M, D’Avanzo R, Scuotto A. Solitary lumbar osteochondroma presenting with spinal cord compression. BMJ case reports. 2013; 2013 20. Schomacher M, Suess O, Kombos T. Osteochondromas of the cervical spine in atypical location. Acta Neurochir. 2009;151(6):629–33. discussion 633. 21. Sekharappa V, Amritanand R, Krishnan V, David KS. Symptomatic solitary osteochondroma of the subaxial cervical spine in a 52-yearold patient. Asian Spine J. 2014;8(1):84–8. 22. Ogul H, Tuncer K, Can CE, Kantarci M. An unusual cause of spinal compression in a young woman: cervical osteochondroma. Spine J. 2014; 14(7):1356. 23. Ofluoglu AE, Abdallah A, Gokcedag A. Solitary osteochondroma arising from cervical spina bifida occulta. Case Rep Orthop. 2013;2013:509745. 24. Er U, Simsek S, Yigitkanli K, Adabag A, Kars HZ. Myelopathy and quadriparesis due to spinal cord compression of C1 laminar osteochondroma. Asian Spine J. 2012;6(1):66–70. 25. Wong K, Bhagat S, Clibbon J, Rai AS. “Globus symptoms”: a rare case of giant osteochondroma of the axis treated with high cervical extrapharyngeal approach. Glob Spine J. 2013;3(2):115–18. 26. Miyachi S, Okamura K, Watanabe M, Inoue N, Nagatani T, Takagi T. Cerebellar stroke due to vertebral artery occlusion after cervical spine trauma. Two Case Rep Spine. 1994;19(1):83–8. 27. Muratsu H, Doita M, Yanagi T, et al. Cerebellar infarction resulting from vertebral artery occlusion associated with a Jefferson fracture. J Spinal Disord Tech. 2005;18(3):293–96.
