Case Report J Korean Orthop Assoc 2012; 47: 305-310 http://dx.doi.org/10.4055/jkoa.2012.47.4.305 www.jkoa.org 악성골종양으로오인된요추의고형동맥류성골낭종 The Solid Variant of the Aneurysmal Bone Cyst in the Lumbar Spine Mimicking a Malignant Bone Tumor 곽윤해 류호동 박혜림 * 김석우한림대학교의과대학한림대학교성심병원정형외과학교실, * 병리학교실 고형동맥류성골낭종은전형적인동맥류성골낭종의약 5-7.5% 를차지하는비교적드문질환으로서고형성분으로인해골육종및골모세포종과같은악성골종양과의감별이어려워그치료계획및예후결정에차이가있으므로임상적으로중요한질환이다. 방사선학적으로전형적인동맥류성골낭종의특징중하나인용액- 용액경계가보이지않으며병리학적으로는기질세포의역형성이관찰되지않아전형적인동맥류성골낭종으로부터고형동맥류성골낭종을감별할수있다. 현재까지척추에서발생한 14예의고형동맥류성골낭종증례를보면전예에서소아청소년에서발생하였으며경추후궁에호발하는전형적인경우에비하여경추및흉, 요추에고루보고되고있다. 본증례에서는하부요통과신경증상을동반한 11년 6개월남환으로서방사선학적검사에서악성골종양으로오인되어이에준한수술전검사를진행하였으며술장소견상악성가능성낮아병소를절제하고경과관찰중에있다. 본증례와문헌고찰을통해악성종양과감별할수있는고형동맥류성골낭종의방사선및병리소견을보고하고자한다. 색인단어 : 요추, 고형동맥류성골낭종, 후궁절제술 동맥류성골낭종은전체골종양의약 1-2% 를차지하는비교적 드문질환으로서국소파괴를동반한낭성병변의형태로관찰된 다. 장골골간부에이어척추에서도 10-20% 발견되며 10 대소아 청소년에서호발하는것으로보고되고있다. 1) 고형동맥류성골 낭종은보다드문형태로서일반동맥류성골낭종에비해방사선 학적으로나병리학적으로감별이힘든것으로알려져있으며, 이 는낭성병변에비해고형성분이우세하여골모세포종, 연골모 세포종의양성골종양에서부터경계성종양인거대세포종그리 고악성골종양인골육종에이르기까지다양한종양과의감별이 쉽지않기때문이다. 2) 국내에서는동맥류성골낭종의호발부위 인원위대퇴부에발생한 1 예만이보고되고있어 3) 요추에서발생 한고형동맥류성골낭종에대한저자들의경험을보고하고자한 다. 접수일 2011 년 12 월 9 일수정일 2012 년 1 월 9 일게재확정일 2012 년 2 월 1 일교신저자김석우안양시동안구관평로 138, 한림대학교성심병원정형외과학교실 TEL 031-380-6000, FAX 031-380-1814 E-mail swkim@hallym.or.kr 증례보고 11년 6개월남아로약한달간의요통과최근발생한우측하지방사통을주소로내원하였다. 과거력상약한달전농구한이후처음증상이발생하였으며타병원에서보존적치료시행후에호전없이최근악화되는하지통증으로전원되었다. 내원당시시행한신체검진상통증부위의국소발열및부종소견은관찰되지않았으나우측제4-5 번요추주위압통및우측하지로방사통이있었으며우측하지직거상검사에서양성이었다. 단순방사선검사상정상적인시상및관상정렬을보였으나측면상에서제4, 5번요추후주에저음영의골파괴소견이보였다. 환아의증상이주로우측늑골척추각 (costovertebral angle) 부위에국한되어신장및척주주위근육의병변가능성에대한감별을위하여우선초음파검사와임상병리검사를시행하였다. 검사상특이소견은관찰되지않았으나초음파검사상하부요추의우측척추후주주위로부터척수강내로침범하는양상의종양이관찰되었으며증가된혈관분포로인해악성골종양이의심되어 (Fig. 1) 입원하여추가검사를진행하였고우선병변부위의자기공명영상및전신골스캔, 흉부전산화단층촬영검사를시행하였다. 자기공명 대한정형외과학회지 : 제 47 권제 4 호 2012 Copyright 2012 by The Korean Orthopaedic Association This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
306 곽윤해 류호동 박혜림외 1 인 Figure 1. Ultrasonography of the pa tient. Partially scanned right posterior paravertebral mass at the lower lumbar area extending into the spinal canal. Figure 3. Computed tomography showed destructive bony lesion in lamina of right 4th lumbar. Figure 2. Magnetic resonance imaging of the patient showed mass lesion with heterogenouos enhancement involving posterior column of L4 and adjacent posterior paravertebral muscle and posterior epidural soft tissue. Figure 4. For selective embolization, right L4 lumbar artery angiography showed round hypervascular tumor staining at the L4, 5 verterbral body level. 영상검사결과약 3 2 3.5 cm 크기의종양으로제4번요추의후궁에서시작하여제4번요추의후궁과인접한척추주위근육, 경막회지방조직을침범하여제5번요추의우측척추경및상부후관절을침범하는병변이관찰되었다. T1 강조영상에서낮은신호강도의종괴로관찰되었으며 T2 강조영상에서고신호강도와저신호강도의병변이산재하는양상으로나타났으며조영증강영상에서는주변의부척추근육과경막외부위의주위연부조직을침범하는불규칙한조영증강 (heterogeneous enhancement) 양상으로관찰되었다 (Fig. 2). 함께시행한전신골스캔및흉부전산화단층촬영상요추이외의타부위병변소견은관찰되지않았 으며전산화단층촬영상병소는피질골을침범하고완전히파괴하여주위연부조직으로풍선과같이팽대되어피질골이얇은계란처럼보였으며낭종과주위골의경계가불분명하여 (Fig. 3) 이상의소견에서골육종 (osteosarcoma) 및골모세포종 (osteoblastoma) 을감별해야할것으로판단되었다. 악성골종양의가능성이있으며종양이척수강을침범하여척수및신경근압박에의한증상이나타난상태로판단되어조직채취를통한병리검사및후방감압술을시행하기위하여수술적치료를계획하였으며수술전제4 요추동맥의색전술 (Fig. 4) 을시행하였다. 약 5 cm의절개로접근하여시행한술장소견상병소조직은적갈색으로병
307 요추의고형동맥류성골낭종 변과정상조직의경계는분명하지않아국소적으로파괴된피질골을포함하여절제하였다. 수술과정에서대량의출혈은관찰되지않았으며수술장에서의냉동조직생검상악성이형성세포는확인되지않아병소내절제및척추궁절제술을시행하였다 (Fig. 5). 최종병리소견상섬유성격막 (fibrous septa) 과함께방추세포의증식 (spindle cell fibroblastic proliferation) 사이로모세혈관들과성숙된유골조직 (osteoid) 의형성, 골모세포로둘러싸인반응성골조직의형성이관찰되었다. 방추세포는낮은분화도로이형성형태는보이지않았으며핵의이상분화및괴사등의악성종양의소견이관찰되지않았다. 다핵거대세포가드문드문산재되어있으며혈액성분을포함한작은동맥류성낭종이간간이관찰되어이상의소견에서고형동맥류성골낭종과일치하는것으로판단했다 (Fig. 6). 수술후환아는요통및하지방사통이호전되었으며약 6주간흉요추보조기를착용한보행을권유하였고재원기간중병리조직검사상양성의골종양인동맥류성골낭종으로확인되어신경학적증세와종양의진행을경과관찰후결 Figure 5. Postoperative plain radiograph after right L4 laminectomy. 정적치료예정하에있다. 고찰 척추에발생하는골종양의약 90% 이상은악성종양의전이소견이며비교적드물게발생하는병변으로공격성양성척추종양의하나로서동맥류성골낭종이있다. 4) 호발연령은 10대의소아청소년으로서방사선학적소견상특징적으로용액- 용액경계 (fluid-fluid level) 가관찰되는것으로알려져있으며활동도가높은초기단계에서는병소의경계가불분명하여악성종양과유사하게보일수있다. 고분화성양성조직으로낭종형태로 T1 강조영상에서중등도, T2 강조영상에서고신호강도를보인다. 4) 고형동맥류성골낭종은낭종이라표현되지만고형성분을주로포함하므로다소역설적용어이다. 수지골및족지골에발생하는경우거대세포반응성육아종 (giant cell reparative granuloma) 이라고도불렸으며일반적인동맥류성골낭종의약 5.0-7.5% 를차지하는것으로알려져있는드문질환이다. 1) Sanerkin 등 2) 이 1983 년에고형동맥류성골낭종이라는용어를처음사용하였으며일반유형과같이장골의골간단부에가장흔하게발생하는것으로알려져있으며모든부위에발생할수있으나척추에발생하는고형동맥류성골낭종또한매우드문병변으로현재까지영어권의약 8논문에서 14예가보고되어있다 (Table 1). 1,2,4-9) 전형적인동맥류성골낭종은자기공명영상상 T1과 T2 영상에서병소의얇고부드러운중격형성의조영증강을보이나고형동맥류성골낭종에서는병소내에서더균질한고신호강도의조영증강을보인다고보고되기도하나 9) 임상증상등으로뚜렷이구분되는특징을보이지않아본증례와같이고형동맥류성골낭종은악성종양으로오인되기도한다. 병리학적으로도거대세포종및골육종과같은악성골종양과의감별이쉽지않은데이는거대세포와방추형기질세포와의분포, 세포충실도 (cellularity) 와다양한유사분열활성 (variable mitotic activity) 에따라진단하기때문이다. 6) 거대세포종에서는주로 20개이상의다양한정도의비정형핵을가진 Figure 6. (A) Blood-filled cavities are lined by osteoclast-like multinucleated giant cells. The intervening stroma is fibroblastic but contains no neoplastic osteoid. (B) Osteoclast-like giant cells are irregularly distributed within the fibroblastic stroma (H&E, 100).
308 곽윤해 류호동 박혜림외 1 인 Table 1. Overview of Reported Cases of Spinal Solid Variant of Aneurysmal Bone Cyst Author (yr) Age/sex Site Imaging Treatment Sanerkin et al (1983) 2) M/7 L4 Expansile cystic lesion in lamina Tumor shelled out laminectomy F/6 T2 Destruction of lamina Partial piecemeal removal M/13 T7 Destruction of lamina with paravertebral mass Subtotal excision, laminectomy, irradiation then currettage and bone graft due to recurrance Buirski and Watt (1984) 5) M/8 L5 Expansile cystic lesion in lamina/soft tissue mass causing L5 root compression F/6 T2 Destructive lytic lesion in lamina/small rim of cortex in left paravertebral area M/14 T7 Destructive lytic lesion in pedicle F/14 C7 Expansile lytic lesion in spinous process Edel et al (1992) 6) F/12 T3-T4 Lytic lesion with destruction of neural arch Excision and complete curettage Oda et al (1992) 7) F/17 T1 Expansile lytic lesion in lamina and spinous process Vergel de Dios et al (1992) 1) Subtotal excision, laminectomy F/16 T7 Lytic lesion in lamina and transverse process Curettage and bone graft/irradiation Spine Sato et al (1996) 8) F/9 L3 Expansile osteolytic lesion in vertebral body, pedicle, transverse process and lamina Irradiation Suzuki et al (2004) 4) F/9 C4 Expansile lytic lesion in lamina Laminectomy, curettage and bone graft Al-Shamy et al (2011) 9) M/18 T2 Expansile osteolytic lesion in vertebral body, lamina, pedicle and rib Present case M/11 L4 Expansile lytic lesion in lamina, paravertebral muscle M, male; F, female. Total spondylectomy with resection of rib and pedicle screw fixation Subtotal excision, laminectomy 거대세포가방추형세포로구성된기질사이에서일정한간격으로분포되어있다. 기질을구성하는방추형세포들도비정형이며과염색성이다. 반면고형동맥류성낭종에서는거대세포가주변의방추세포들사이에불규칙적으로분포되어있으며방추세포의핵도비정형성이없기에조직학적으로감별이된다. 또한골육종과는달리고형동맥류성낭종에서는양성의골모세포와반응성골소주가관찰되며핵의과염색성이나비정형성이없다. 일반적인동맥류성낭종과는혈액성분으로채워진큰공간이없이고형물질을갖고있다는점에서차이가있다. 10) 본증례에서는악성종양의소견인비정형핵및과염색성이없었으며불규칙한분포의거대세포, 유골조직및반응성골조직의형성, 낮은분화도의방추세포가관찰되어최종적으로고형동맥류성골낭종으로진단되었다. 진단이확정된후에치료는척추에발생하는일반적인동맥류성골낭종과같이수술적접근에의한병소내완전절제및골이식술이가장좋은치료로알려져있으며그외선택적색전술및경과관찰, 수술후방사선치료등이사용되고있다. 1) 기존의연구에서동맥류성골낭종의치료후재발은술후 20% 에서, 방사선단독요법에서 25% 정도로알려져있고수술적치료의경우불완전절제이후수개월이내에발생하는것으로알려져있으며완전절제가이루어진경우높은완치율을보인다 고한다. 방사선치료를동반할시골육종, 성장판손상및방사선성척수증등의합병증을유발할수있어소아청소년환아에서시행시수술적절제가불가능한경우에한하여제한적으로고려해야할것이다. 8) 그러나현재까지고형동맥류성골낭종의경우에는증례로만보고되고있어치료과정이확립되지는않아기존의동맥류성골낭종에준해치료를시행하고자하였다. 본환아의경우병소내절제생검및후궁절제술을통해수술후통증과신경학적증상이호전되었으며제4, 5 요추의병소의위치로인하여완전절제시후방기기고정이불가피한상태였으나동맥류성골낭종이양성종양이며드물게자연퇴행이보고된바있어신경학적증세와종양의진행을경과관찰중이나불완전한절제시 30% 이상의재발률을보이기때문에추후근치수술및후방기기고정의시행이필요할수있을것으로생각한다. 고형동맥류성골낭종은낭성병변외에고형성분으로인해방사선학적검사상골육종등의악성골종양과의감별이필요하고병리학적으로도거대세포종과유사하여진단에어려움이있으나비교적드물게발생하여본증례와같이악성종양으로오인할수있다. 임상적으로경막외연부조직의침범을동반한악성골종양과양성골종양의치료방향과예후에큰차이가있으므로영상의학과, 정형외과그리고병리과의협의진료하에드문
309 요추의고형동맥류성골낭종 아형인고형동맥류성골낭종에대한이해가필요할것으로생각하여본증례를보고하는바이다. 참고문헌 1. Vergel De Dios AM, Bond JR, Shives TC, McLeod RA, Unni KK. Aneurysmal bone cyst. A clinicopathologic study of 238 cases. Cancer. 1992;69:2921-31. 2. Sanerkin NG, Mott MG, Roylance J. An unusual intraosseous lesion with fibroblastic, osteoclastic, osteoblastic, aneurysmal and fibromyxoid elements. "Solid" variant of aneurysmal bone cyst. Cancer. 1983;51:2278-86. 3. Kim HY, Park JH, Lee BK, Han TI, Kang DW, Choy WS. Solid variant of aneurysmal bone cyst (a case report). J Korean Bone Joint Tumor Soc. 1998;4:216-20. 4. Suzuki M, Satoh T, Nishida J, et al. Solid variant of aneurysmal bone cyst of the cervical spine. Spine (Phila Pa 1976). 2004;29:E376-81. 5. Buirski G, Watt I. The radiological features of "solid" aneurysmal bone cysts. Br J Radiol. 1984;57:1057-65. 6. Edel G, Roessner A, Blasius S, Erlemann R. "Solid" variant of aneurysmal bone cyst. Pathol Res Pract. 1992;188:791-6. 7. Oda Y, Tsuneyoshi M, Shinohara N. "Solid" variant of aneurysmal bone cyst (extragnathic giant cell reparative granuloma) in the axial skeleton and long bones. A study of its morphologic spectrum and distinction from allied giant cell lesions. Cancer. 1992;70:2642-9. 8. Sato K, Sugiura H, Yamamura S, Takahashi M, Nagasaka T, Fukatsu T. Solid variant of an aneurysmal bone cyst (giant cell reparative granuloma) of the 3rd lumbar vertebra. Nagoya J Med Sci. 1996;59:159-65. 9. Al-Shamy G, Relyea K, Adesina A, et al. Solid variant of aneurysmal bone cyst of the thoracic spine: a case report. J Med Case Rep. 2011;5:261. 10. Vester H, Wegener B, Weiler C, Baur-Melnyk A, Jansson V, Dürr HR. First report of a solid variant of aneurysmal bone cyst in the os sacrum. Skeletal Radiol. 2010;39:73-7.
310 곽윤해 류호동 박혜림외 1 인 The Solid Variant of the Aneurysmal Bone Cyst in the Lumbar Spine Mimicking a Malignant Bone Tumor Yoon Hae Kwak, M.D., Ho-Dong Lyu, M.D., Hye-Rim Park, M.D.*, and Seok Woo Kim, M.D. Departments of Orthopedic Surgery, *Pathology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea The Solid variant of the aneurysmal bone cyst is clinically important, because its solid composition is comparable to that observed in osteosarcoma or osteoblastoma, presenting difficulty for the correct diagnosis. The fluid-fluid level, which is a common sign of the conventional aneurismal bone cyst, is not apparent in radiographs of the solid type. These cysts were localized, equally within the whole spine as compared to most conventional aneurysmal bone cysts in which are localized to the posterior neural arch of the cervical spine. In this particular patient case, a young male aged 11.5 years presented with lower back pain and radiating pain which was misdiagnosed as a malignant bone tumor. Surgical intervention was considered and the incisional biopsy and laminectomy were conducted due to the low possibility of malignancy. We present this case and literature reviews with radiological and pathological findings as an example of the differential diagnosis of malignant tumors. Key words: spine, aneurysmal bone cyst, laminectomy Received December 9, 2011 Revised January 9, 2012 Accepted February 1, 2012 Correspondence to: Seok Woo Kim, M.D. Department of Orthopedic Surgery, Hallym University Sacred Heart Hospital, 138, Gwanpyeong-ro, Dongan-gu, Anyang 431-070, Korea TEL: +82-31-380-6000 FAX: +82-31-380-1814 E-mail: swkim@hallym.or.kr