Aneurysmal Bone Cyst

Home , Aneurysmal bone cyst, Osteoid, Osteolysis

Review Article Aneurysmal Bone Cyst

Abstract Timothy B. Rapp, MD Aneurysmal bone cysts are rare skeletal tumors that most James P. Ward, MD commonly occur in the first two decades of life. They primarily develop about the knee but may arise in any portion of the axial or Michael J. Alaia, MD appendicular skeleton. Pathogenesis of these tumors remains controversial and may be vascular, traumatic, or genetic. Radiographic features include a dilated, radiolucent lesion typically located within the metaphyseal portion of the bone, with fluid-fluid levels visible on MRI. Histologic features include blood-filled lakes interposed between fibrous stromata. Differential diagnosis includes conditions such as telangiectatic osteosarcoma and giant cell tumor. The mainstay of treatment is curettage and bone graft, with From the Department of Orthopaedic Surgery, NYU Hospital or without adjuvant treatment. Other management options include for Joint Diseases, New York, NY. cryotherapy, sclerotherapy, radionuclide ablation, and en bloc Dr. Rapp or an immediate family resection. The recurrence rate is low after appropriate treatment; member has received research or however, more than one procedure may be required to completely institutional support from AO Spine, Arthrex, the Arthritis Foundation, the eradicate the lesion. Arthritis National Research Foundation, Asterland, Biomet, DePuy, Encore Medical, Exactech, DJO, Ferring Pharmaceuticals, the neurysmal bone cysts (ABCs) cate the lesion completely while si- Geisinger Foundation, Integra Awere first described in 1942 by multaneously preserving as much of LifeSciences, Johnson & Johnson, Jaffe and Lichtenstein,1 who coined the normal host bone as possible. KCI, Medtronic, the National the term aneurysmal cyst because of Institutes of Health, OMeGA, the Orthopaedic Research and the pathologic appearance of the le- Education Foundation, the sion within bone. These bone lesions Pathophysiology Orthopaedic Trauma Association, are benign and are typically associ- the Osteosynthesis and Trauma Much debate exists regarding the na- ated with pain, swelling, or the pres- Care Foundation, Paradigm Spine, ture of ABCs. Dabska and Buraczew- Progenics Pharmaceuticals, Small ence of an expansile mass. ABCs are ski11 were among the first to com- Bone Innovations, Smith & Nephew, considered primary lesions in ap- ment on the pathophysiology and Stryker, Surgix, and Synthes, and proximately 70% of cases, with the serves as a board member, owner, natural history of the ABC. They di- officer, or committee member of the remaining 30% arising secondary to vided its progression into four 2 American Academy of Orthopaedic different primary tumors. phases, with the initial phase de- Surgeons. Neither of the following The patient with ABC most com- scribed as osteolysis of the marginal authors nor any immediate family monly presents in the first two de- member has received anything of part of the bone with discrete eleva- value from or owns stock in a cades of life. Common lesion sites in- tion of the periosteum. The growth commercial company or institution clude the femur, tibia, fibula, phase is characterized by the pro- related directly or indirectly to the humerus, skull, and posterior ele- gressive destruction of bone. Demar- subject of this article: Dr. Ward and ments of the spine. Multiple theories Dr. Alaia. cation of the lesion is poor during have been proposed regarding the this phase; bony shells and septations J Am Acad Orthop Surg 2012;20: pathophysiology of ABC, including 233-241 may not be obvious on plain radio- vascular, traumatic, and genetic graphs. The stabilization phase is de- http://dx.doi.org/10.5435/ etiologies.3-8 Primary ABC has a low JAAOS-20-04-233 fined by the classic ABC appearance: incidence rate, ranging from 0.14 to an expansile lesion with a distinct Copyright 2012 by the American 0.32 per 100,000 individuals.6,9,10 bony shell and osseous septations. In Academy of Orthopaedic Surgeons. The goal of management is to eradi- the healing phase, progressive ossifi-

April 2012, Vol 20, No 4 233 Aneurysmal Bone Cyst cation of the lesion is obvious and of immunohistochemistry and in situ results in a bony mass with a some- hybridization in 19 specimens of Classiﬁcation what irregular structure. ABC. They found insulin-like growth Several classification systems have Campanacci et al3 described the le- factor-I or mRNA coding for this been developed to categorize ABCs. sion as a response to local hemor- growth factor primarily localized in Enneking13 divided lesions into three rhage. An initial insult produces in- multinucleate giant cells in all of the stages: inactive, active, and aggres- traosseous bleeding, leading to the specimens. Insignificant levels of ex- sive. The inactive tumor is the most formation of a cyst. The cyst walls pression were found in normal hu- benign because the lesion is con- may house capillaries that hemor- man bone tissue. These findings sup- tained. Expansion is rare, and there rhage into the newly formed cavity, port the theory that genetic factors is minimal inflammation or perios- producing osteolytic and repair tis- may play a significant role in the de- teal reaction. An active lesion typi- sue, which may ultimately explain cally produces mild symptoms such the lesion’s predilection for rapid, ag- velopment of primary ABC. as pain, with expansion and cortical gressive expansion. Lichtenstein4 thinning as well as a layer of reactive proposed that the ABC is a reactive Clinical Presentation bone separating the lesion from nor- lesion rather than a true neoplasm mal bone visible on radiographs. Ag- and that vascular disturbances in In patients with ABC, age of onset gressive tumors are rapidly expansile bone lead to increased intraosseous ranges from 1 to 59 years, with the and destroy surrounding tissues. pressure, causing local destruction greatest prevalence between ages 12 This subtype is typically the most and distension of bone. Ratcliffe and 9,10 and 13 years. Typically, males are symptomatic. Grimer5 described the formation of affected more often than females, Capanna et al14 based their system an ABC at a fracture site in a previ- with reported ratios ranging from on five morphologic subgroups (Fig- ously normal tibia. Like Capanacci 1:1.04 to 1.8:1.9,10 In a population- ure 1). Type I lesions are centrally lo- et al3 and Lichtenstein,4 the authors based analysis of 110 surgically cated and well contained, with either postulated that the fracture altered treated ABC patients listed in the Vi- no outline or a slightly expanded the intraosseous blood flow and sub- outline. Type II lesions have marked sequently led to formation of the le- enna Bone Tumor Registry, 73 ABCs expansion and cortical thinning with sion. (66%) occurred in patients younger 9 involvement of the entire bony seg- Recently, genetics have been impli- than age 20 years. ment. Type III lesions are eccentric cated in the etiology of ABC, leading The patient with primary ABC typ- and metaphyseal and typically in- some to believe that ABC is a true ically reports pain and may present volve only one cortex. Type IV le- neoplasm rather than a reactive pro- with soft-tissue swelling or a palpa- sions are the least common subgroup cess. In a histopathologic study, Ol- ble expansile mass. As with most be- and develop subperiosteally, expand- iveira et al6 reported that gene rear- nign bony malignancies, secondary ing away from the bone. Type V le- rangements localized to t(16;17) in symptoms such as fever, weight loss, sions occur periosteally and expand 36 of 52 primary ABCs (69%) in malaise, nausea, or vomiting are not peripherally, ultimately penetrating which the ubiquitin-specific protease common. cortical bone. 6 oncogene was placed under the ABC commonly arises at sites such regulatory influence of the highly ac- as the femur, tibia, humerus, and fib- tive cadherin-11 promoter. They ula; these sites account for approxi- Imaging found no such translocations in 17 mately 52% of ABC sites.10 Other cases of secondary ABC. The authors common locations include the skull Suspected ABC can be evaluated ini- concluded that these findings con- and spinal column, with ABC being tially with plain radiography. The firm a true neoplastic etiology. Oth- one of the most common malignan- classic radiographic appearance of ers have shown that upregulation of cies (along with osteoid osteoma and ABC is a radiolucent cystic lesion ubiquitin-specific protease 6 may osteoblastoma) that affect the poste- within the metaphyseal portion of induce matrix metalloproteinase pro- rior elements of the spine. In chil- the bone. The lesion is destructive duction by activation of nuclear fac- dren, the most common sites of ex- and may expand into the surround- tor κ-light-chain-enhancer of acti- tremity ABC are the femur and ing cortical bone. The mass may ele- vated B cells, which ultimately leads tibia.2,12 ABCs in these areas are typi- vate the periosteum, but it typically to tumorigenesis.7 cally confined to the metaphyseal re- remains contained by a thin shell of Leithner et al8 reported the results gions of the bone. cortex. Typically, ABCs are eccentric

234 Journal of the American Academy of Orthopaedic Surgeons Timothy B. Rapp, MD, et al

Figure 1

Illustration of the aneurysmal bone cyst classiﬁcation developed by Capanna et al,14 based on morphologic changes visible on radiographs. (Redrawn with permission from Dormans JP, Hanna BG, Johnston DR, Khurana JS: Surgical treatment and recurrence rate of aneurismal bone cysts in children. Clin Orthop Relat Res 2004;[421]:205-211.)

Figure 2

AP (A) and lateral (B) radiographs demonstrating an expansile metaphyseal lesion of the distal ulna with thinning of the bony cortices and internal septations in a 46-year-old man who presented with a painful mass on the distal forearm. C, Axial fat-saturated T2-weighted magnetic resonance image demonstrating fluid-fluid levels consistent with an aneurysmal bone cyst (ABC). Histology confirmed ABC. D, Postoperative AP fluoroscopic image of the distal ulna following en bloc resection.

but may also be central or subperios- layering of solid blood components for diagnosis of ABC, Mahnken et teal. Lesions in the epiphysis should within cystic areas of the lesion (Fig- al15 compared the sensitivity and raise suspicion of secondary changes ures 2 and 3). This finding is highly specificity of MRI alone with that of caused by a different neoplastic pro- suggestive of an ABC but is not conventional radiography with MRI. cess.14 Occasionally, CT is used pre- pathognomonic because it is also a They found that MRI was superior operatively to better define the bony radiographic characteristic of telan- to conventional radiography in terms limits of the lesion. MRI with con- giectatic osteosarcoma (TOS), giant of specificity. However, the sensitiv- trast typically demonstrates internal cell tumor, secondary ABC, and frac- ity, specificity, and positive predictive septations that may contain charac- ture through a simple cyst. In a study value were greatest when both mo- teristic fluid-fluid levels, signifying of the value of radiography and MRI dalities were used in concert.

April 2012, Vol 20, No 4 235 Aneurysmal Bone Cyst

Figure 3 however, are histologically similar to the solid portion of the classic ABC. Currently, incisional biopsy with histologic evaluation is the standard for diagnosis of ABC. Creager et al17 retrospectively reviewed 23 histologic specimens from 23 patients with ABCs who were initially evaluated with fine needle aspiration biopsy (FNAB). In 6 cases (26%), the aspirates were insufficient for diagnosis. They concluded that FNAB was associated with an unacceptably high risk of missed diagnosis and found that radiologic correlation of the findings increased the accuracy of FNAB.

Differential Diagnosis

Differential diagnosis of ABC includes benign lesions, such as unicameral bone cysts, or tumorous lesions, such as chondromyxoid fibroma, chondroblastoma, giant cell tumor, or osteoblastoma. It is neces- sary to distinguish ABCs from these benign lesions because up to 30% of ABCs are ABC-like lesions arising from other primary tumors.2 ABC A, AP radiograph of the distal femur demonstrating a well-defined metaphyseal lytic lesion in a 26-year-old man who reported left knee pain must be differentiated from TOS, and swelling for 6 months. Axial noncontrast CT (B) and axial fat-saturated given their radiographic and histo- T2-weighted magnetic resonance image (C) of the same lesion logic similarities (Table 1). In a retro- demonstrating internal septations, fluid-fluid levels, and thinning and erosion of the posterior cortex with minimal soft-tissue expansion. Curettage with spective review of 40 pathologically cryotherapy and subsequent bone grafting, cementing, and internal fixation confirmed cases of TOS, Murphey were performed. D, Postoperative AP radiograph of the distal femur following et al18 reported thick, nodular en- curettage, grafting, and internal fixation. hancement of the tissue surrounding cystic spaces on contrast MRI and CT consistent with TOS. This nodular enhancement was associated with of ABC reveals hemorrhagic tissue high-grade sarcomatous tissue and Histology with cavitary spaces separated by fi- hemorrhagic, necrotic spaces. These brous septa composed of spindle Dabska and Buraczewski11 were identifying features could also be cells, inflammatory cells, and a seen before contrast was adminis- among the first to describe the histo- smaller percentage of giant cells (Fig- tered in 32 cases (80%). In contrast, pathology of ABCs as that of a cav- ure 4). Osteoid formation with or ABC has a thin peripheral rim and ernous vascular tumor ranging from without osteoblastic rimming may be septal enhancement without signifi- a few millimeters to 1 to 2 cm in di- noted. In a clinicopathologic study of cant nodularity. Histologically, TOS ameter, with intralesional communi- 238 patients with ABCs, 5% to 10% is characterized by blood-filled lakes, cating cavitations without blood of lesions were solid with little to no areas of necrosis, and giant cells. clots. Typically, microscopic analysis cystic formation.16 These lesions, Most importantly, TOS has areas of

236 Journal of the American Academy of Orthopaedic Surgeons Timothy B. Rapp, MD, et al pleomorphism and atypical mitotic be required for small, peripherally Curettage and Bone figures that are visible under high- based tumors. Lesions that involve Grafting power microscope magnification the spine should be treated in consul- Currently, curettage and bone graft- (Figure 5). Osteoids may or may not tation with an experienced spine sur- ing with or without adjuvant therapy be present. Accurate diagnosis is es- geon. Long-term clinical and radio- is the accepted method for manage- sential because the prognosis and graphic follow-up is required to ment of ABC.16 In the literature, the treatment of ABCs are significantly assess for recurrence and to monitor description of curettage ranges from different than those of TOS and function. Spontaneous resolution of creation of either a small fenestration other malignant lesions of bone. ABCs has been reported.19 or large cortical windows in the cyst

Figure 4 Management

Diagnosis of ABC must be confirmed histologically before initiating defini- tive treatment. Once the diagnosis is established, management generally consists of intralesional curettage and bone grafting, with or without adjuvant therapy. Adjuvant treatment is intended to treat microscopic disease contamination within the tumor bed to lower the incidence of local recurrence. Wide resection and reconstruction Histologic images of the aneurysmal bone cyst (ABC) in the patient shown in can be considered for lesions that Figure 2. A, Low-power image demonstrating numerous blood-filled cystic have destroyed the metaphyseal bone spaces lined and separated by fibrous septa, confirming the diagnosis of ABC (hematoxylin-eosin, magnification ×4). B, High-power image in periarticular areas. For large tu- demonstrating abundant multinucleated osteoclast-type giant cells (arrows) mors in the axial skeleton and pelvis, within a dense background of bland fibroblastic cells in the septae preoperative embolization can be (hematoxylin-eosin, magnification ×20). Cystic cavities may also be appreciated at this power. (Courtesy of Syed T. Hoda, MD, Stony Brook, NY, considered to minimize intraopera- and Luigia C. Abramovici, MD, New York, NY.) tive bleeding; embolization may not

Table 1 Characteristics and Management of Aneurysmal Bone Cyst and Telangiectatic Osteosarcoma Lesion

Factor Aneurysmal Bone Cyst Telangiectatic Osteosarcoma

Typical age at onset (yr) 10–20 10–20 Location Femur, tibia, fibula, humerus Distal femur, proximal tibia, proximal humerus Radiographic appearance Radiography demonstrates a metaphyseal, Radiography demonstrates a metaphyseal, lytic, eccentric, lucent, cystic lesion that may have and invasive lesion that may have a balloon- a balloon-like appearance like appearance MRI demonstrates fluid-fluid levels MRI demonstrates fluid-fluid levels Histologic appearance Blood-filled spaces separated by thin fibrous Blood-filled spaces separated by thicker fibrous septa with benign-appearing spindle cells septa, with malignant-appearing cells more Osteoid with or without osteoblastic rimming easily noted at higher magnification Inflammatory cells and giant cells may be Pleomorphism, atypical mitotic figures, and present possible osteoid formation Management Curettage with adjuvant sclerotherapy, emobo- Neoadjuvant chemotherapy, wide surgical resec- lization, or en bloc resection tion and reconstruction, postoperative chemotherapy

April 2012, Vol 20, No 4 237 Aneurysmal Bone Cyst

Figure 5 dynamic disturbance were controlled. In a prospective randomized study, Varshney et al25 evaluated 94 patients treated with either sclerotherapy with polidocanol or curettage with high-speed burr and bone grafting. The average follow-up was 4.4 years. The sclerotherapy group had a 93.3% healing rate compared with 84.8% in the curettage group. The authors determined that the sclerotherapy group had a similar rate of recurrence but better functional out- comes and fewer complications (eg, A, Low-power histologic image demonstrating hypercellularity, a blood-filled cavity, and osteoid formation on the left in a patient with telangiectatic deep or superficial infection, growth osteosarcoma (TOS; hematoxylin-eosin, magnification ×10). B, High-power disturbances) than did the curettage histologic image demonstrating areas of hypercellularity, blood-filled cystic group. Complications unique to the cavities, and the presence of a small amount of unmineralized osteoid in a sclerotherapy group include local in- patient with a TOS (hematoxylin-eosin, magnification ×20). Note the significant cellular atypia that clearly distinguishes this lesion from a benign duration at the injection site and hy- ABC. (Courtesy of Syed T. Hoda, MD, Stony Brook, NY, and Luigia C. popigmentation. Patients who under- Abramovici, MD, New York, NY.) went sclerotherapy required a higher number of repeat procedures to achieve healing than did those to complete saucerization. Sauceriza- compared with four recurrences in treated with curettage. This finding tion is preferred when a strut of cor- four cases treated with curettage and has been reported in other similar tical bone may be preserved to allow bone grafting alone. Complications studies, although the underlying maintenance of the structural integ- associated with curettage are often mechanism of failure has not been 12,21,22,25,26 rity of the bone. Cottalorda and related to incomplete resection of the elucidated. In a retrospec- 20 Bourelle found that curettage lesion and resultant recurrence. tive study of 72 patients with ABCs through a small fenestration in the treated with percutaneous sclerother- 26 cyst led to a higher rate of recurrence Cryotherapy apy with polidocanol, Rastogi et al and should be avoided. Gibbs et al21 reported a mean clinical response of found that curettage with a high- Use of cryotherapy has been found to 84.5%; however, patients required speed burr reduced the incidence of reduce the recurrence rate of ABC. In an average of three injections. recurrence independent of the type of a retrospective review of 27 ABCs Ethibloc (Ethnor Laboratories/ graft (eg, cancellous autograft, can- treated with curettage and cryotherapy, Ethicon, Norderstedt, Germany), a 23 cellous allograft, polymethyl methac- Schreuder et al reported a 3.7% local fibrogenic and thrombogenic rylate) used. The authors reported rate of recurrence. Similarly, Peeters agent that was initially used for vas- 24 that 4 of 34 patients with ABCs et al reviewed 80 consecutive cases cular embolization, is another possi- (12%) who underwent curettage had of ABC treated with curettage and ble sclerotherapy agent. Adamsbaum a local recurrence, whereas no pa- cryotherapy. At an average follow-up et al27 reviewed 17 patients with tient who underwent complete exci- of 55 months, the authors found ABC who were treated with Ethibloc sion of the cyst had a recurrence. only four local recurrences for an injection. At a 5-year follow-up, 14 The authors found that recurrence overall rate of 5%. These recurrences patients (82.4%) achieved complete was associated with young age and were all successfully treated with re- healing. However, 16 patients open growth plates. peat curettage and cryosurgery. (94.1%) had local inflammatory re- Garg et al22 retrospectively evalu- actions, and 3 (17.6%) developed ated ABCs of the spine and reported Sclerotherapy small cutaneous fistulae. Ethibloc no recurrences in eight cases treated Sclerotherapy is a noninvasive man- has been associated with severe com- with a surgical technique using in- agement method based on the theory plications, including pulmonary em- tralesional curettage, electrocautery, that ABCs arise as a vascular malfor- bolism and aseptic fistulae that re- high-speed burr, and bone grafting mation and would heal if the hemo- quire incision and drainage.28 A fatal

238 Journal of the American Academy of Orthopaedic Surgeons Timothy B. Rapp, MD, et al case of cerebellar infarct following cause inadvertent embolization of Several risk factors have been im- Ethibloc injection into a cyst in the the artery of Adamkiewicz could plicated in the high rate of ABC re- atlas has also been reported.29 Given lead to cord ischemia and anterior currence. In several clinical series, the rate of severe complications, cord syndrome; therefore, the sur- younger age (ie, <12 years) has been some authors consider Ethibloc in- geon must make every attempt to vi- associated with an increased risk of jection an alternative to surgery sualize this artery to prevent inadver- recurrence.21,35,36 Dormans et al,12 rather than a first-line treatment. tent embolization. however, did not find a significant difference in the recurrence rate in Radionuclide Ablation En Bloc Resection patients older or younger than age 10 years. Open physes also have Recently, radionuclide ablation has En bloc resection has been associated been associated with an increased been proposed for management of with the lowest rate of recurrence af- risk of recurrence after curettage ABC. This method has been used ter initial treatment compared with with a high speed burr; this may be successfully to manage other diseases other management methods. Unfor- due to less aggressive curettage of the such as rheumatic synovitis and re- tunately, this technique is not always area because of the fear of inducing current hemarthroses associated with feasible due to the location of the le- growth arrest.21 Despite the in- hemophilia. Interest in this modality sion and its proximity to other vital creased risk, some do not believe has grown given the radiosensitivity structures. In a study of 238 patients 16 that more aggressive management is of ABCs and the ability of radionu- with ABC, Vergel De Dios et al warranted because the risk of com- clide ablation to control disease found that none of the 16 patients plications such as violation of articu- within a cavity. Bush et al30 retro- who underwent wide excision of the lar cartilage or destruction of the spectively reviewed five patients with lesion demonstrated a recurrence. 32 physis could predispose the patient large ABCs treated with a CT-guided Campanacci et al reviewed 198 to future angular deformity or limb- injection of chromic phosphate P32. cases of ABC and found no recur- 36 The patients were followed for more rence in the 47 cases treated with length discrepancy. than 2 years. The authors reported partial or total resection. Harrop Histologic evaluation may serve as 33 successful control of the lesion with et al reviewed the management of a prognostic indicator of recurrence. 37 one injection in four patients and a aggressive benign lesions of the Docquier et al determined the like- complete success rate after two injec- spine, including ABC, and strongly lihood of recurrence based on the tions. Although this method is prom- recommended complete excision; proportion of cellular tissue (ie, giant ising, additional research is required however, the surgeon must be wary cells, stromal cells) relative to the before it may be considered as a of the potential need for fusion due amount of osteoid (ie, bone matrix) first-line treatment for ABC. to iatrogenic instability. Although en and fibrillar components (ie, fibro- bloc resection has the lowest rate of blasts, collagen) in 21 biopsy sam- Arterial Embolization recurrence compared with other ples. The authors compared the ratio management methods, this method of osteoid and fibroblastic compo- The results of selective arterial embo- is reserved for ABCs in expend- lization for management of ABC nents with the cellular content of able bone locations (eg, fibula, clavi- each specimen. Recurrent ABCs had have also been evaluated. In a retro- cle) and can be performed without spective study of 36 patients with a predominantly cellular component. negatively affecting cosmesis or func- When the osteoid component pre- ABCs treated with arterial embolization. tion, Rossi et al31 found that 32 pa- dominated, the prognosis was good tients (94%) had full resolution of because the cyst was presumed to be the lesion on radiographic and clini- Recurrence in a healing phase. cal examination. Of these cases, 14 Mitotic indices may also have required more than one emboliza- In a long-term study of 150 ABCs prognostic value. Ruiter et al38 found tion. Two cases of skin necrosis were treated over 20 years, Mankin et al34 that the recurrence rate of ABCs was reported; one required flap coverage. reported a local recurrence rate of significantly higher in cases with a Risk factors associated with the need approximately 20%. Patients in this mitotic index of ≥7 per 50 fields than for repeat embolization were age <16 series were treated primarily with cu- in those with a lower mitotic index. years or lesions >5 cm in size. Le- rettage and either implantation of al- Other histologic factors that have sions in the thoracic or upper lumbar lograft chips or polymethyl methac- been associated with recurrence in- spine require a careful approach be- rylate. clude the presence of an immature

April 2012, Vol 20, No 4 239 Aneurysmal Bone Cyst lace pattern and fibromyxoid nodu- use of these modalities. However, 7. Ye Y, Pringle LM, Lau AW, et al: lar fasciitis-like areas.39 there is paucity of prospective ran- TRE17/USP6 oncogene translocated in aneurysmal bone cyst induces matrix domized controlled studies that di- metalloproteinase production via rectly compare treatment modalities; activation of NF-kappaB. Oncogene Malignant Transformation 2010;29(25):3619-3629. thus, treatment is typically guided by surgeon preference. 8. Leithner A, Lang S, Windhager R, et al: A small number of malignant trans- Expression of insulin-like growth factor-I formations of ABCs have been re- (IGF-I) in aneurysmal bone cyst. Mod Pathol 2001;14(11):1100-1104. ported. Some reports were associated Acknowledgment with the use of adjuvant radiation in 9. Zehetgruber H, Bittner B, Gruber D, 40 et al: Prevalence of aneurysmal and addition to primary treatment. The authors would like to thank solitary bone cysts in young patients. Brindley et al40 reported on two cases Clin Orthop Relat Res 2005;439:136- Syed T. Hoda, MD, and Luigia C. 143. of malignant transformation that oc- Abramovici, MD, for contributing curred 5.5 and 12 years, respectively, 10. Leithner A, Windhager R, Lang S, Haas histology slides to this article. OA, Kainberger F, Kotz R: Aneurysmal after the ABCs were managed with bone cyst: A population based intralesional curettage without adju- epidemiologic study and literature review. Clin Orthop Relat Res 1999; vant radiation. A TOS and fibroblas- References (363):176-179. tic osteosarcoma, respectively, were 11. Dabska M, Buraczewski J: Aneurysmal identified at the sites of the ABC. Evidence-based Medicine: Levels of bone cyst: Pathology, clinical course and These cases demonstrate the need for evidence are described in the table of radiologic appearances. Cancer 1969; 23(2):371-389. continued long-term follow-up, espe- contents. In this article, reference 26 cially if symptoms recur or change. 12. Dormans JP, Hanna BG, Johnston DR, is a level II study. Reference 36 is a Khurana JS: Surgical treatment and level III study. Reference 37 is a level recurrence rate of aneurysmal bone cysts IV study. in children. Clin Orthop Relat Res 2004; Summary (421):205-211. References printed in bold type are 13. Enneking WF: A system of staging ABCs are benign, active lesions that those published within the past 5 musculoskeletal neoplasms. Clin Orthop may cause significant morbidity in years. Relat Res 1986;(204):9-24. children and adults. Although the 14. Capanna R, Bettelli G, Biagini R, 1. Jaffe HL, Lichtenstein L: Solitary risk of malignant transformation is Ruggieri P, Bertoni F, Campanacci M: unicameral bone cyst: With emphasis on Aneurysmal cysts of long bones. Ital J very rare, these lesions are typically the roentgen picture, the pathologic Orthop Traumatol 1985;11(4):409-417. appearance and the pathogenesis. Arch managed surgically, with the primary Surg 1942;44:1004-1025. 15. Mahnken AH, Nolte-Ernsting CC, goals of completely eradicating the Wildberger JE, et al: Aneurysmal bone 2. Cottalorda J, Kohler R, Sales de Gauzy J, lesion and minimizing the risk of re- cyst: Value of MR imaging and et al: Epidemiology of aneurysmal bone conventional radiography. Eur Radiol currence. Secondary goals are im- cyst in children: A multicenter study and 2003;13(5):1118-1124. literature review. J Pediatr Orthop B proved function and resolution of 2004;13(6):389-394. 16. Vergel De Dios AM, Bond JR, Shives pain. Compared with other manage- TC, McLeod RA, Unni KK: Aneurysmal 3. Campanacci M, Bertoni F, Bacchini P: ment methods, excision of the pri- bone cyst: A clinicopathologic study of Aneurysmal bone cysts, in Campanacci 238 cases. Cancer 1992;69(12):2921- mary lesion is associated with the M, Bertoni F, Bacchini P, eds: Bone and 2931. Soft Tissue Tumors. Vienna, Austria, lowest rate of recurrence, although Springer, 1990. 17. Creager AJ, Madden CR, Bergman S, this method is not always feasible Geisinger KR: Aneurysmal bone cyst: 4. Lichtenstein L: Aneurysmal bone cyst: A from a functional standpoint. Fine-needle aspiration findings in 23 pathologic entity commonly mistaken for patients with clinical and radiologic Currently, open curettage with ad- giant cell tumor and occasionally for correlation. Am J Clin Pathol 2007; hemangioma and osteogenic sarcoma. 128(5):740-745. juvant therapy and bone grafting is Cancer 1950;3:279-289. the most widely accepted manage- 18. Murphey MD, wan Jaovisidha S, Temple 5. Ratcliffe PJ, Grimer RJ: Aneurysmal ment option. It has a low rate of re- HT, Gannon FH, Jelinek JS, Malawer bone cyst arising after tibial fracture: A MM: Telangiectatic osteosarcoma: currence, with minimal risk to the case report. J Bone Joint Surg Am 1993; Radiologic-pathologic comparison. 75(8):1225-1227. function of the affected area. Re- Radiology 2003;229(2):545-553. cently, other treatments have gained 6. Oliveira AM, Perez-Atayde AR, Inwards 19. McQueen MM, Chalmers J, Smith GD: CY, et al: USP6 and CDH11 oncogenes attention, including sclerotherapy, Spontaneous healing of aneurysmal bone identify the neoplastic cell in primary cysts: A report of two cases. J Bone Joint radionuclide ablation, and selective aneurysmal bone cysts and are absent in Surg Br 1985;67(2):310-312. so-called secondary aneurysmal bone arterial embolization. Excellent suc- cysts. Am J Pathol 2004;165(5):1773- 20. Cottalorda J, Bourelle S: Current cess rates have been reported with 1780. treatments of primary aneurysmal bone

240 Journal of the American Academy of Orthopaedic Surgeons Timothy B. Rapp, MD, et al

cysts. J Pediatr Orthop B 2006;15(3): 27. Adamsbaum C, Mascard E, 34. Mankin HJ, Hornicek FJ, Ortiz-Cruz E, 155-167. Guinebretière JM, Kalifa G, Dubousset J: Villafuerte J, Gebhardt MC: Aneurysmal Intralesional Ethibloc injections in bone cyst: A review of 150 patients. 21. Gibbs CP Jr, Hefele MC, Peabody TD, primary aneurysmal bone cysts: An J Clin Oncol 2005;23(27):6756-6762. Montag AG, Aithal V, Simon MA: efficient and safe treatment. Skeletal Aneurysmal bone cyst of the extremities: Radiol 2003;32(10):559-566. 35. Bas¸arir K, Pis¸kin A, Güçlü B, Yildiz Y, Factors related to local recurrence after Sag˘lik Y: Aneurysmal bone cyst curettage with a high-speed burr. J Bone 28. Topouchian V, Mazda K, Hamze B, recurrence in children: A review of 56 Joint Surg Am 1999;81(12):1671-1678. Laredo JD, Penneçot GF: Aneurysmal patients. J Pediatr Orthop 2007;27(8): bone cysts in children: Complications of 938-943. 22. Garg S, Mehta S, Dormans JP: Modern fibrosing agent injection. Radiology surgical treatment of primary 2004;232(2):522-526. 36. Lin PP, Brown C, Raymond AK, Deavers aneurysmal bone cyst of the spine in MT, Yasko AW: Aneurysmal bone cysts children and adolescents. J Pediatr 29. Peraud A, Drake JM, Armstrong D, recur at juxtaphyseal locations in Orthop 2005;25(3):387-392. Hedden D, Babyn P, Wilson G: Fatal skeletally immature patients. Clin ethibloc embolization of vertebrobasilar Orthop Relat Res 2008;466(3):722-728. 23. Schreuder HW, Veth RP, Pruszczynski system following percutaneous injection M, Lemmens JA, Koops HS, Molenaar into aneurysmal bone cyst of the second 37. Docquier PL, Delloye C, Galant C: WM: Aneurysmal bone cysts treated by cervical vertebra. AJNR Am J Histology can be predictive of the curettage, cryotherapy and bone Neuroradiol 2004;25(6):1116-1120. clinical course of a primary aneurysmal grafting. J Bone Joint Surg Br 1997; bone cyst. Arch Orthop Trauma Surg 79(1):20-25. 30. Bush CH, Adler Z, Drane WE, Tamurian 2010;130(4):481-487. R, Scarborough MT, Gibbs CP: 24. Peeters SP, Van der Geest IC, de Rooy Percutaneous radionuclide ablation of 38. Ruiter DJ, van Rijssel TG, van der Velde JW, Veth RP, Schreuder HW: axial aneurysmal bone cysts. AJR Am J EA: Aneurysmal bone cysts: A Aneurysmal bone cyst: The role of Roentgenol 2010;194(1):W84-90. clinicopathological study of 105 cases. cryosurgery as local adjuvant treatment. Cancer 1977;39(5):2231-2239. J Surg Oncol 2009;100(8):719-724. 31. Rossi G, Rimondi E, Bartalena T, et al: Selective arterial embolization of 36 39. de Silva MV, Raby N, Reid R: 25. Varshney MK, Rastogi S, Khan SA, aneurysmal bone cysts of the skeleton Fibromyxoid areas and immature osteoid Trikha V: Is sclerotherapy better than with N-2-butyl cyanoacrylate. Skeletal are associated with recurrence of intralesional excision for treating Radiol 2010;39(2):161-167. primary aneurysmal bone cysts. aneurysmal bone cysts? Clin Orthop Histopathology 2003;43(2):180-188. Relat Res 2010;468(6):1649-1659. 32. Campanacci M, Capanna R, Picci P: Unicameral and aneurysmal bone cysts. 40. Brindley GW, Greene JF Jr, Frankel LS: 26. Rastogi S, Varshney MK, Trikha V, Clin Orthop Relat Res 1986;(204):25- Case reports: Malignant transformation Khan SA, Choudhury B, Safaya R: 36. of aneurysmal bone cysts. Clin Orthop Treatment of aneurysmal bone cysts with Relat Res 2005;438:282-287. percutaneous sclerotherapy using 33. Harrop JS, Schmidt MH, Boriani S, polidocanol: A review of 72 cases with Shaffrey CI: Aggressive “benign” long-term follow-up. J Bone Joint Surg primary spine neoplasms: Br 2006;88(9):1212-1216. Osteoblastoma, aneurysmal bone cyst, and giant cell tumor. Spine (Phila Pa 1976) 2009;34(22 suppl):S39-S47.

April 2012, Vol 20, No 4 241