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Tumors and Tumor-like Conditions of the Spine in Children Sumeet Garg, MD, and John P. Dormans, MD Dr. Garg is Resident, Department of Abstract Tumors and tumor-like conditions of the spine, although rare, should be included in the differential diagnosis of infants and chil-dren with back pain. Skeletal pathology is more frequently the cause of back pain in children than in adults. Although most tu-mors and tumor-like conditions of the spine in children are benign, many require surgery. Children with malignant tumors of the spine (with the exception of leukemia and lymphoma) may require mul-timodality therapy, including surgery, to achieve long-term cure. Advances in imaging, surgical technique, surgical technology, and adjuvant therapy have led to improvements in diagnosis and treat-ment and, thus, outcomes. In many cases, however, early and accu-rate diagnosis is often possible based on only clinical history, physi- cal examination, and plain radiographic imaging. Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO. Dr. Dormans is Chief, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, and Professor of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA. None of the following authors or the departments with which they are affiliated has received anything of value from or owns stock in a commercial company or institution related directly or indirectly to the subject of this article: Dr. Garg and Dr. Dormans. Reprint requests: John P. Dormans, MD, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Wood Building, 2nd Floor, Philadelphia, PA 19104. J Am Acad Orthop Surg 2005;13:372-381 Copyright 2005 by the American Academy of Orthopaedic Surgeons. he incidence of bone pathology (except degeneration) is rela-tively low in adults with back pain even though these patients may un-dergo extensive workup for their symptoms. In children, however, structural pathology is the most common cause of back pain.1 Physi-cians therefore initially must under-take a thorough history and physical examination and acquire plain radio-graphs of the spine. Nevertheless, the differential diagnosis of back pain in children is broad (Table 1). Although tumors overall are respon-sible for only a small fraction of vis-its for back pain in children, tumors of the spine represent 2% to 8% of all musculoskeletal tumors.2,3 Despite their rarity, proper under- standing of these tumors is essential foranyorthopaedicsurgeoncaringfor children. The ability to distinguish among benign tumors with a favor-able natural history, benign tumors with locally aggressive behavior, and malignant lesions is equally impor-tant. The clinician often may be able toreasonablyassessthetypeoflesion after an initial evaluation and ap-praisal of plain radiographs. Because most spine tumors are benign, an in-formed diagnosis in the initial stages of assessment often relieves the fam-ily and child of unnecessary anxiety. Although patients with spinal column bone tumors invariably present with back pain, patients with spinal cord tumors may not. Spinal cord tumors are classified as extramedullary, extramedullary in-tradural,andintramedullary4 (Fig.1). Although most patients with spinal cord tumors will be treated by a neu-rosurgeon, children with such tu-mors often first present to an ortho-paedic surgeon. A high index of suspicion is required to identify these tumors early, thereby improv-ing the child’s chance of survival and minimizing, with prompt surgery, possible functional impairment. 372 Journal of the American Academy of Orthopaedic Surgeons Sumeet Garg, MD, and John P. Dormans, MD Table 1 Differential Diagnosis of Back Pain in Children Common Muscular strain/apophysitis/ overuse Spondylolysis Spondylolisthesis Trauma: microfracture Less common Infection (diskitis/osteomyelitis) Scheurmann disease Trauma: fracture Uncommon Herniated nucleus pulposus Ankylosing spondylitis Juvenile rheumatoid arthritis Bone tumor Spinal cord tumor Psychogenic Figure 1 Classification of spinal cord tumors. Examples of specific tumors are listed beneath their classification. (Adapted with permission from McComb J, Liker M, Levy M: Spinal cord tumors, in Weinstein S [ed]: The Pediatric Spine: Principles and Practice, ed 2. Philadelphia, PA: Lippincott, Williams, & Wilkins, 2001, pp 709-740.) Clinical Presentation and Diagnosis History teomareportintensefocalbackpain, occurring most often at night, that markedly improves following use of aspirin or nonsteroidal anti-inflam-matory drugs (NSAIDs). Osteochon- compromise resulting from extrinsic compression from the bone tumor, compromiseofvascularsupplytothe spinal cord because of tumor, or the presence of a spinal cord tumor. Most children diagnosed with dromas are an exception to the gen- Back pain is also a frequent pre- bone tumors of the spine present with back pain. In a series of 257 children and adults with bone tu-mors of the spine, 96% presented with an initial report of back pain.5 When evaluating a child for back pain, it is essential to obtain a de-tailed history and a thorough review of systems (Table 2). Certain features of back pain suggest an underlying tumor rather than a non-neoplastic diagnosis. Tumor-related pain often will be focal, occur at night, wake the child from sleep, and increase in intensity over time, and it may be unrelated temporally to activity. A warning sign for locally aggressive or malignant tumors is very rapid in-crease in intensity of pain over a short period or any pain of severe in-tensity. Constitutional symptoms also may be present in children with malignant tumors. eralruleofearlysymptomswithbony tumorsofthespine.Usuallytheyare painless until they reach a size that impinges on surrounding soft tissue, thespinalcord,ornerveroots,result-ing in radicular pain that is more prominent than focal back pain. Neurologic complaints are infre-quent in children with bone tumors of the spine. Of all benign bone tu-mors, only aneurysmal bone cysts and giant cell tumors have a >25% prevalence of neurologic symptoms at presentation.6-8 In nearly 50% of cases, osteoblastoma of the thoracic spine also may present with neuro-logic symptoms.9 Although neuro-logic symptoms are uncommon in children with bone tumors of the spine, they may present in tandem with pain in children with malignant bony spine tumors and spinal cord tumors. A thorough neurologic his- senting symptom in spinal cord tu-mors. For intramedullary spinal cord tumors, in particular, back pain is of-ten a very late symptom of the dis-ease. Sixty-seven percent of children with intramedullary spinal cord tu-mors report back pain, but only 10% will have radicular pain.10 The report of radicular pain may suggest the presenceofanextramedullarytumor or a bone tumor that is compressing nerve roots. In many cases, children with intramedullary spinal cord tu-mors first present with scoliosis, tor-ticollis, gait abnormality, or other neurologic abnormality. For this rea-son, they are initially seen by an or-thopaedic surgeon rather than a neu-rologist or neurosurgeon. Parents of infants should be asked certain specific questions (Table 2). Infants with spinal cord tumors of-ten present in very subtle ways, such Certain patterns of pain may even tory should be taken (Table 2). Posi- as irritability, pseudoparesis (de-suggest a specific type of tumor. For tive answers to questions about neu- creased motor activity in the ex-example, children with osteoid os- rologicsymptomssuggestspinalcord tremities), early development of Volume 13, Number 6, October 2005 373 Tumors and Tumor-like Conditions of the Spine in Children Table 2 Differential Diagnosis of Back Pain in Children Pain characteristics Is there a history of trauma? When did the pain begin? Is the pain present at night? Do you ever wake up from a sound sleep in pain? What is the intensity of the pain? Is the pain sporadic or constant? Has the intensity of the pain increased or decreased over time? Are there any medications that relieve the pain? Are there any other alleviating or aggravating factors? Is there pain anywhere besides the back or neck? Do any medications help the pain? Neurologic symptoms Do you feel “pins and needles” in your arms or legs? Do you have any weakness in your arms or legs? Do you have any shooting pains down your arms or legs? Do you have any trouble with your bowel or bladder function? Specific questions for parents or guardians of infants Has your child been irritable? Has your child decreased or stopped use of an extremity? Has your child developed a gait abnormality? Has your child lost or had delayed acquisition of developmental milestones? Has your child developed or switched hand preference? Has your child had any recent fevers? Has your child lost weight? struction.Scoliosisoccursin>40%of children with spine tumors. In os-teoid osteoma (10% of cases occur in the spine) and osteoblastoma (40% occur in the spine), scoliosis is thought to be a muscular response to pain.11,12 The curve generally has its apexatthelevelofthetumor;thetu-mor also typically is located on the convex side of the deformity. Chil-dren with bone tumors also may present with scoliosis when the tu-morsleadtoasymmetricvertebralde-struction—as,forexample,inLanger-hans cell histiocytosis (formerly called eosinophilic granuloma), os-teosarcoma, or other lytic bone tu-mors. Childrenwithspinalcordtumors, by contrast, frequently develop scoliosis before onset of pain. In a study of orthopaedic aspects of spi-nal cord tumors, Tachdjian and Mat-son13 found 31 of 115 children (27%) with spinal cord tumors to have scoliosis at presentation. The scoli-osis is thought to be the result of ir-ritation of nerve roots because of tu-mor. In contrast, scoliosis associated with osteoid osteoma and osteoblas-toma is thought to result from irrita-tion and inflammation of paraspinal hand preference (preference is rare before age 2 years), and loss or de-layed acquisition of developmental milestones. Parents or guardians of any child presenting with neurolog-ic symptoms also should be asked whether there is a history of lumbar puncture during infancy; lumbar adolescents, the examination should begin with observation of the child’s gait. Gait abnormalities can be the first sign of a spinal tumor, especial-ly in younger children. The child is asked to walk on the heels and then on the toes as a quick screen for strength and balance. Following ob- muscles.12 The pattern of scoliosis is also important because left thoracic curves are unusual in patients with idiopathic scoliosis. Any child with left thoracic scoliosis should be care-fully evaluated and should undergo MRI to assess for spinal cord pathol-ogy. In addition, Tachdjian and Mat- puncture, especially without the use servation of the gait, the child’s son13 found that torticollis was of a stylet, is a risk factor for later de-velopment of an epidermoid tumor. Taking a careful and complete clin-ical history will not normally allow a clinician to diagnose a specific spine tumor, but it will raise or low-er suspicion that a tumor is present and help direct subsequent workup. Physical Examination Physical examination is useful in spine should be examined for any skin changes, dysraphisms, or defor-mity. Sacral dimples can mark the presence of either a dermoid or epi-dermoid tumor. When the sinus tract cannot be followed to a closed end, magnetic resonance imaging (MRI) is required to evaluate for the possibility of a spinal cord tumor. Spinaldeformities(scoliosisorky-phosis)frequentlydevelopinchildren sometimes present in children with spinal cord tumors: 21 of 115 chil-dren (18%) in their series had torti-collis at presentation. A complete neurologic examina-tion is essential in the workup of any child with back pain or neurologic symptoms. Approximately 20% of children with bone tumors of the spine and up to 50% of children with spinal cord tumors will have motor distinguishing between tumors of with spine tumors. Deformity is the weakness on physical examina- the bony spine and those of the spi-nal cord. For walking children and result of either a muscular response to pain or asymmetric vertebral de- tion.13,14 In contrast, sensory deficit is less prevalent at presentation 374 Journal of the American Academy of Orthopaedic Surgeons Sumeet Garg, MD, and John P. Dormans, MD among children with spine tumors and, when present, suggests a spinal cord tumor. Long tract signs also should be elicited by testing for deep tendon reflexes, spasticity, and clo-nus. In addition, the abdominal re-flexmaybeasymmetricasaresultof spinal cord pathology and should be checked routinely. The presence of long tract signs usually points to a spinal cord lesion rather than a le-sion of the bony spine. Skin examination is important in the diagnosis of neurofibromatosis, the most common single gene disor-der in humans. One of the diagnostic signs of neurofibromatosis is the presence of café-au-lait spots. Other skin signs include axillary or in-guinal freckling. Children with neu-rofibromatosis invariably have mul-tiple tumors in the spinal cord.15 Most are asymptomatic; however, as the tumors increase in size, they can cause compression of nerve roots and can result in the development of serious neurologic deficits. Skin and soft-tissue examination alsoisneededtoevaluateforthepres-enceofanymasses.Mostnotably,os-teochondromas,osteoblastomas,and malignancies may grow sufficiently in size to create a palpable mass. Spi-nalosteochondromasaremorelikely to develop in children with multiple hereditary exostoses than as isolated solitarylesions.16 Childrenwithneu-rofibromatosisusuallyhavemultiple cutaneousneurofibromasthatcanbe palpatedtoaidinmakingthediagno-sis.Inchildren,massesresultingfrom neurofibromasandosteochondromas that are not compressing the spinal cord or nerve roots usually are pain-less.Childrenwithmalignantperiph-eral nerve sheath tumors, however, usually have masses that are tender topalpation.Thesoft-tissuemassas-sociatedwithEwing’ssarcomaofthe spinecanbeeitherpainfulorpainless to palpation. Radiographic Evaluation The results of the history and physical examination dictate which Volume 13, Number 6, October 2005 imaging should be obtained. Al-thoughmanychildrencometotheor-thopaedic surgeon with several ad-vancedstudiesalreadycompleted,the following guidelines may be helpful. All children with back pain that has persisted for more than 4 weeks or is associated with concerning features, such as night pain or neurologic symptoms, should have anteroposte-rior and lateral radiographs made of the painful spinal segment. When plain radiographs are negative in a child with only back or neck pain, a bonescanmaybeusefulindetermin-ing whether any spinal pathology ex-ists.Inchildrenwithsuspectedlocal-ized bone pathology, a computed tomography(CT)scangivesexcellent anatomic detail of the spine and can suggest a specific diagnosis. Any child with a spinal deformity found on examination should have 3-footweight-bearinganteroposterior and lateral plain radiographs made of the entire spine. If any neurologic deficit is appreciated on examination or elicited on history, an MRI scan should be done to assess the spinal canal and spinal cord. MRI also is helpful in evaluating bone tumors of the spine, particularly when malig-nancy is suspected, because MRI can visualize soft-tissue and marrow bet-terthanCT.Forsuspectedosteoidos-teoma, osteoblastoma, or osteochon-droma, fine-cut CT (3-mm slices) is preferred because of its high resolu-tion of osseous tissue. Diagnostic Imaging Although the clinical history and physical examination may suggest the presence of a spinal tumor, imag-ing is the tool that often allows the cliniciantomakeaconfidentdiagno-sis of the specific type of tumor. In some cases, the appearance of the le-sion on plain radiographs, when con-sidered with the clinical history and physical examination, points to a de-finitive diagnosis. In other cases, ad-vanced imaging, such as CT or MRI, Figure 2 Plain anteroposterior radiograph of the thoracic spine demonstrating the “winking owl” sign in an 8-year-old girl with an aneurysmal bone cyst at T5. The left pedicle of T5 is missing (arrow). may be needed to determine the di-agnosis. Most children with spinal tumors have positive findings on plain radio-graphs by the time they present to the orthopaedic surgeon with symp-toms or signs such as back pain or scoliosis. In one retrospective review of 82 patients with bone tumors of the spine, 99% were found on initial plain radiographs to have abnormal-ities.17 Among the specific findings are scoliosis, kyphosis, loss of lum-bar lordosis, destruction of pedicles (“winking owl” sign) (Fig. 2), con-genital vertebral anomalies, lytic lesions, altered size of neural foram-ina, abnormal calcifications, and soft-tissue masses. The location of any abnormalities should be noted because certain tumors have a predi-lection for either the anterior or pos-teriorelementsofthespine(Table3). The age of the patient also may aid in formulating a differential diagno-sis (Table 4). This information, along with the finding of certain features suggestive of specific tumors of the spine, often can allow the clinician to make a confident diagnosis with-out the need for biopsy. Osteoid osteoma usually appears onplainradiographsasasmallradio- 375 Tumors and Tumor-like Conditions of the Spine in Children Table 3 Figure 3 Common Locations of Spine Tumors Anterior Elements Giant cell tumor Langerhans cell histiocytosis Leukemia Lymphoma Posterior Elements Aneurysmal bone cyst (may extend anterior) Osteochondroma Osteoblastoma Osteoid osteoma Table 4 Typical Age Distribution of Spine Tumors in Children Age (yrs) 0-5 5-10 10-18 Benign Langerhans cell histiocytosis Aneurysmal bone cyst Langerhans cell histiocytosis Osteoblastoma Osteoid osteoma Aneurysmal bone cyst Osteochondroma Osteoid osteoma Malignant Ewing’s sarcoma Leukemia Neuroblastoma (metastatic) Wilms’ tumor (metastatic) Ewing’s sarcoma Osteosarcoma Ewing’s sarcoma Osteosarcoma Axial CT scan at L1 in a 13-year-old boy with an osteoblastoma. Note the expansile nature of the lesion and growth into the spinal canal. The child presented with back pain and prominent lower extremity weakness. Figure 4 lucent nidus with a sclerotic rim. more extensive involvement and ag-Osteoblastoma, which is identical gressive behavior. Alternatively, histologically to osteoid osteoma, appears larger. Whereas osteoid os-teomas tend to be more sclerotic, os-teoblastomas are more expansile11 (Fig. 3). In general, most lesions <10 mm in diameter are classified as os-teoid osteoma; lesions >20 mm in di-ameter are classified as osteoblasto-ma; and those between 10 to 20 mm are deemed indeterminate. Indeter-minate lesions require close review of the clinical and radiographic fea-tures for a diagnosis. A child with a classic presentation for osteoid os-teoma (night pain relieved by aspirin or NSAIDs) should have a fine-cut CT scan (2- or 3-mm slices) done of the spine (Fig. 4). Standard CT cuts may miss the small nidus of osteoid osteomas. A fine-cut CT image near-ly always accurately identifies the nidus and usually gives a definitive diagnosis; by contrast, an MRI scan may be misinterpreted to suggest when plain radiographs are normal and there is a high suspicion of os-teoid osteoma, a bone scan should be obtained. Bone scans are highly sen-sitive in localizing osteoid osteoma to a specific spinal level, after which CT scan can precisely delineate the location of the tumor. Langerhans cell histiocytosis (LCH) of the spine may present with a vertebra plana on plain radiograph. Vertebra plana is complete vertebral collapse with preservation of disk space and usually with lack of asso-ciated soft-tissue mass (Fig. 5). The collapse may be total or partial. LCH may be present at multiple levels of the spine, may involve other axial or appendicular sites of the skeleton, or may have an associated soft-tissue mass. A bone scan or skeletal survey undertaken to evaluate for multiple sites of disease should be done in any child with suspected LCH because Axial CT scan at C5 in a 12-year-old girl with an osteoid osteoma of the left pedicle. The arrow indicates the center of the lesion (nidus). The nonlesional, reactive sclerotic bony rim around the nidus (arrowhead) is characteristic of osteoid osteoma on CT. multiple sites occur in up to 50% of cases.18,19 Vertebral collapse, howev-er, also can be seen in a wide variety of spine tumors, including malig-nancies such as Ewing’s sarcoma, lymphoma, and metastatic neuro-blastoma. MRI is helpful in distin-guishing LCH from these malignan-cies because LCH will most often 376 Journal of the American Academy of Orthopaedic Surgeons ... - tailieumienphi.vn