Aneurysmal bone cyst of the extremities. Factors related to local recurrence after curettage with a high-speed burr

Unicameral (simple) and aneurysmal bone cysts: the effect of insufficient curettage on recurrence

INTRODUCTION

Curettage of the cyst and bone grafting are the most common methods used in the treatment of unicameral bone cysts (UBC) and aneurysmal bone cysts (ABC). Recurrence of these cysts is often associated with insufficient curettage of the cyst during surgery. In this study, we aimed to evaluate the effect of insufficient curettage on recurrence in patients with UBC and ABC.

METHODS

The retrospective study included 18 patients with UBC and 14 patients with ABC that were surgically treated by curettage and bone grafting in our clinic between 2006-2013. Mean age was 19.80 (range, 4-50) years in the patients with UBC and 21.76 (range, 4-56) in the patients with ABC. The diagnosis of the cysts was established both clinically and radiologically. Mean follow-up period was 36 (range, 6-60) months both in the patients with UBC and ABC. The patients with recurrence underwent a second curettage and grafting procedure. Healing and recurrence were evaluated according to modified Neer's scale.

RESULTS

Recurrence occurred in 8 patients. Of these, 5 patients underwent a second curettage and grafting procedure and 3 patients were lost to follow-up. Complete healing occurred in all the patients that underwent a second curettage and grafting procedure.

CONCLUSION

The achievement of complete healing in the patients that underwent a second curettage and grafting procedure indicates that the recurrence of UBC and ABC is associated with insufficient curettage.

Aneurysmal bone cyst of the metatarsal: A case report

An aneurysmal bone cyst (ABC) is a rare, non-neoplastic, destructive, hemorrhagic and expansile lesion accounting for 1% of all bone tumors. This type of lesion predominantly affects long bones and vertebrae. ABC of the metatarsal is rare and only a few cases have been reported in the literature to date. The present study reports a rare case of ABC of the third metatarsal occurring in a 27-year-old male patient, who presented with repeated foot swelling that had lasted for ~1 year. Other clinical manifestations included limping, multiple lumps (defined as masses on or below the skin, as detected by imageological diagnosis) and progressively increasing local pain in his right foot. Magnetic resonance imaging of the right metatarsal revealed a segmented, expansile, multiseptated lesion with fluid-fluid levels. An en bloc resection was performed and the defect was replaced with a tricortical iliac autograft. Pathological analysis of the resected tissue suggested ABC. The present study aims to describe a case of ABC of the metatarsal, a condition that often poses a diagnostic challenge, and to underline the importance of radiological and histological examinations for the accuracy of that diagnosis.

A treatment strategy for proximal femoral benign bone lesions in children and recommended surgical procedures: retrospective analysis of 62 patients

PURPOSE

We aimed to develop a surgical treatment strategy for benign bone lesions of the proximal femur based upon retrospective review of our data in 62 children.

METHODS

Sixty-two children [38 male, 24 female; median age 9 years (range 5-18 years)] with proximal femoral benign bone lesions were surgically treated between 2005 and 2013. Histopathological diagnoses were simple (31) or aneurysmal (27) bone cysts, and nonossifying fibromas (4). The pathological fracture rate was 77.4 %. Surgical treatment was determined due to four criteria, including patient's skeletal maturity, localization and initial diagnosis of lesion, and amount of bone loss in the femoral neck and lateral proximal femur. Surgical procedure consisted of biopsy, curettage, bone grafting, and internal fixation when required. The median follow-up was 45 months (range 25-89 months).

RESULTS

Complete clinical recovery was achieved in 56 (90.3 %) patients between 4 and 8 months postoperatively; full weight-bearing and mobilization, without pain and limping, was possible. The median preoperative and postoperative last follow-up Musculoskeletal Tumor Society (MSTS) scores were 13.3 % (range 10-23.3 %) and 96.6 % (range 90-100 %), respectively (p < 0.0001). The pathological fractures were healed in 10 weeks on average (range 8-12 weeks). Fifty-seven (92 %) patients demonstrated complete or significant partial radiographic healing between 5 and 7 months that maintained throughout follow-up. Local recurrence was not observed, and only 1 (1.6 %) patient required reoperation for partial cyst healing. There were 5 (8 %) complications, 1 (1.6 %) of which required reoperation.

CONCLUSIONS

This treatment strategy can provide good local control and excellent functional and radiological results in the management of benign bone lesions of the proximal femur in children.

Can ethanol be used as an adjuvant to extended curettage in order to reduce the recurrence rate of aneurysmal bone cyst?

OBJECTIVE

The best treatment of aneurysmal bone cyst (ABC) is still unclear. This study aimed to evaluate the usefulness of extended curettage and ethanol as an adjuvant to reduce local recurrence of ABCs.

METHODS

Retrospectively, 68 cases treated for primary and secondary ABCs caused by benign tumors from 2003 to 2013 were enrolled to a follow-up visit between one to ten years after the surgery. The treatment protocol was en-bloc resection, biopsy and curettage, extended curettage consisted of curettage, high-speed burring, ethanol 96%, and electrocauterization (combined four-step alcohol-using approach) followed by defect filling, consecutively.

RESULTS

Among 36 patients with primary ABCs (16 male, 20 female, mean age of 16 years, range 3-46 years), 29 cases were treated with the combined four-step alcohol-using approach, four patients with resection, and three with biopsy and curettage. Thirty-two cases had secondary ABCs on benign lesions (17 male, 15 female). The recurrence rate was 5.88 in all primary and secondary ABC cases; two recurrences among 29 patients with primary ABCs (6.9%) and one recurrence among the 22 cases with secondary ABCs (4.5%).

CONCLUSIONS

It could be suggested that the combined four-step alcohol-using approach may result in a very low recurrence rate of primary and secondary ABC lesions.

Primary Epiphyseal Aneurysmal Bone Cyst Of Distal Ulna

Introduction:

Aneurysmal Bone Cyst (ABC) is a benign expansile cystic blood filled reactive lesion of the bone, most common in the first 2 decades of life. Though it can involve any bone in the body but tibia, humerus, femur and posterior elements of spine are most commonly affected. They most commonly involve metaphysis or metaphysio-diaphyseal part of the bone. Primary involvement of epiphysis is rarely reported. Here we present a case of 6 year old male child with an epiphyseal ABC of distal ulna. Its diagnosis, surgical management, clinical outcome with review of literature is discussed.

Percutaneous Doxycycline Treatment of Juxtaphyseal Aneurysmal Bone Cysts

BACKGROUND

A recurrence rate of 19% to 23% has been reported in juxtaphyseal aneurysmal bone cysts (ABC) without en bloc resection or amputation. No percutaneous surgical techniques or drug treatments have demonstrated consistent bone healing with normal physeal growth and a recurrence rate of <19%. Doxycycline has properties that may make it an appropriate agent for percutaneous treatment of juxtaphyseal ABC in skeletally immature patients.

METHODS

We retrospectively reviewed 16 patients who underwent percutaneous treatment of ABCs with doxycycline from 2006 to 2011. The mean age was 7.1 years (range, 2 to 15 y). There were 16 treatment locations: humerus (9), tibia (3), fibula (2), femur (1), and ulna (1). Sixteen patients completed treatment involving 102 treatment sessions (2 to 14 sessions per patient). Treatment response was evaluated radiographically by measuring the lytic component, thickness of involved cortex, and signs of bony remodeling, and evidence of physeal growth arrest. Recurrence was indicated by new areas of lytic destruction after completion of treatment. The minimum follow-up was 18 months (mean, 39 mo).

RESULTS

All 16 patients demonstrated reduction in lytic destruction, bony healing, and bony remodeling. One patient demonstrated recurrent minimal lytic destruction after 20 months of observation. Seven patients (7/16, 44%) demonstrated physeal ABC involvement; 5 of 7 patients healed with a physeal bone bridge, all ≤15% of the physeal surface area, 1 with mild central physeal deformity. All patients with focal transphyseal ABC involvement (4/4, 100%) demonstrated focal bone bridge after treatment. No patient had diffuse physeal growth arrest; only patients with intraphyseal or transphyseal ABC involvement had focal physeal growth arrest.

CONCLUSIONS

In this series, patients undergoing percutaneous doxycycline treatment of juxtaphyseal ABCs demonstrated ABC healing and a recurrence rate of 6% at >18 months. Patients without physeal ABC involvement demonstrated no evidence of physeal growth arrest.

Surgical treatment of active or aggressive aneurysmal bone cysts in children

The aim of this study was to evaluate functional and radiological results, tumor control, and complications of the surgical treatment of aneurysmal bone cysts (ABCs) in children by extended curettage using a mechanical burr and cauterization, grafting, and internal fixation in specific locations. Sixty-four children [38 males, 26 females, median age=10 years (range, 5-18 years)] with active or aggressive ABCs of long and flat bones were subjected to a median follow-up of 66 months (range, 28-130 months) following surgical treatment. The pathological fracture rate was 72%. Surgical procedures included intralesional extended curettage (92%) or en-bloc resection (8%). Internal fixation was required in 53%. The pathological fractures healed successfully in 8-12 weeks. The median Musculoskeletal Tumor Society (MSTS) score at the last follow-up was 95% (range, 55-100%). Treatment failure (partial healing/recurrence) and complication rates following extended curettage were 7 and 5.2%, respectively. Statistically, the only parameter affecting partial healing and local recurrence was proximity of the lesion to the growth plate (P=0.011). Extended curettage using a mechanical burr and cauterization, grafting, and internal fixation in specific locations can promote healing in most cases of ABC, with low recurrence and complication rates.

Is curettage and high-speed burring sufficient treatment for aneurysmal bone cysts?

BACKGROUND

To decrease the recurrence rate after intralesional curettage for aneurysmal bone cysts, different adjuvant treatments have been recommended. Liquid nitrogen spray and argon beam coagulation have provided the lowest recurrence rates, but unlike the high-speed burr, these adjuvants are not always available in operating rooms.

QUESTIONS/PURPOSES

We asked: (1) Is high-speed burring alone sufficient as an adjuvant to curettage with respect to recurrence rates? (2) What is the complication rate from this technique? (3) What are the risk factors for local recurrence?

METHODS

A retrospective review of the database of the University Musculoskeletal Tumor Unit and the private files of the senior author (EHW) for a period of 19 years (1993-2011) was performed to identify all patients histologically diagnosed with primary aneurysmal bone cyst. During that period, patients with aneurysmal bone cysts were treated with intralesional curettage, burring, and bone grafting if the lesions showed an adequate cortical wall or a wall with thinned out portions which could be reconstructed with bone grafting. Based on those indications, we treated 54 patients for this condition. Of those, 18 were treated using approaches other than burring because they did not meet the defined indications, and an additional five patients were lost to followup before 2 years, leaving 31 patients for analysis, all of whom were followed up for at least 2 years (mean, 7 years; range, 2-18 years).

RESULTS

Of these 31 patients, one had a recurrence (3.2%). Complications using this approach occurred in three patients (9.7%), and included growth plate deformity (1) and genu varus (2) secondary to collapse of the reconstructed condyle. With only one recurrence, we cannot answer what the risk factors might be for recurrence; however, the one patient with recurrence presented with a large lesion and a pathologic fracture.

CONCLUSIONS

Curettage, burring, and bone grafting compare favorably in the literature with other approaches for aneurysmal bone cysts, such as cryotherapy and argon-beam coagulation. We conclude that high-speed burring alone as an adjuvant to intralesional curettage is a reasonable approach to achieving a low recurrence rate for aneurysmal bone cysts.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Treatment of a unicameral bone cyst in a dog using a customized titanium device

A 4-year-old Shih-Tzu, referred for an enlarged left carpus, was diagnosed with a unicameral bone cyst. A customized titanium device was inserted into cystic lesion and fixed by titanium screws. Sufficient strength of the affected bone with the device inserted to maintain limb function was established after resection of contents of cystic lesion. There was no deterioration of the lesion of bone cyst, and acceptable function of the affected limb with no clinical signs of lameness was maintained during 36 months follow-up. The results of this study demonstrated that bone cyst curettage and use of a customized titanium device could provide an effective alternative treatment of huge lesion of unicameral bone cysts with the intent of preventing pathologic fractures.

Upper extremity considerations for oncologic surgery

It was estimated that more than 3000 people would be diagnosed with a primary bone or joint malignancy and more than 11,000 people would be diagnosed with a soft tissue sarcoma in 2013. Although primary bone and soft tissue tumors of the upper extremity are infrequent, it is imperative that the clinician be familiar with a systematic approach to the diagnosis and treatment of these conditions to prevent inadvertently compromising patient outcome. With advances in chemotherapy, radiotherapy, tumor imaging, and surgical reconstructive options, limb salvage surgery is estimated to be feasible in 95% of extremity bone or soft tissue sarcomas.

Subperiosteal resection of fibular aneurysmal bone cyst

Aneurysmal bone cyst (ABC) of the fibula poses a challenge as to the most appropriate treatment particularly in children and adolescents. A prospective study was conducted to evaluate the results of subperiosteal resection of fibular ABCs. Eleven patients (six boys and five girls) with an average age of 12.4 years (6-18 years) were treated by subperiosteal resection of ABC of the fibula. The lesion was juxtaphyseal in three patients (two distal and one proximal), metaphyseal in seven and diaphyseal in one. All cysts were active and centrally located type 2. The modified Enneking scoring system was used for final functional evaluation while a scale proposed by the author was used for final radiological assessment. At the final follow-up, there was no difference in the range of movement, alignment or stability of the ankle or the knee when compared with the opposite side. Three patients complained of mild discomfort on heavy activity. One patient had failure of healing that was related to the use of suction drain. After a mean follow-up of 41.6 months (24-64 months), the mean functional score was 98.8% (93-100%). According to the proposed radiological scale, six patients were rated excellent, three good, one fair and one poor. In conclusion, subperiosteal resection is effective in eradicating fibular ABCs, regenerates a new bone and avoids the morbidity of other techniques.

Aneurysmal bone cysts of the spine: treatment options and considerations

Aneurysmal bone cysts (ABCs) are benign bone lesions with annual incidences ranging from 1.4 to 3.2 cases per million people. Approximately, 10-30% of ABCs are found in the spine. Such lesions are traditionally treated with curettage or other intralesional techniques. Because ABCs can be locally aggressive, intralesional resection can be incomplete and result in recurrence. This has led to increased use of novel techniques, including selective arterial embolization (SAE). This study aims to: (1) compare outcomes based on extent of surgical resection, and (2) compare the efficacy of SAE versus surgical resection. Clinical data pertaining to 71 cases of spinal ABCs were ambispectively collected from nine institutions in Europe, North America, and Australia. Twenty-two spinal ABCs were treated with surgery, 32 received preoperative embolization and surgery, and 17 were treated with SAE. Most tumors were classified as Enneking stage 2 (n = 29, 41%) and stage 3 (n = 29, 41%). Local recurrence and survival were investigated and a significant difference was not observed between treatment groups. However, all three local recurrences occurred following surgical resection. Surgical resection was further categorized based on Enneking appropriateness. Recurrences only occurred following intralesional Enneking inappropriate (EI) resections (P = 0.10), a classification that characterized 47% of all surgical resections. Furthermore, 56% of intralesional resections were EI, compared to only 10% of en bloc resections (P = 0.01). Although SAE treatment did not result in any local recurrences, 35% involved more than five embolization procedures. Spinal ABCs can be effectively treated with intralesional resection, en bloc resection, or SAE. Preoperative embolization should be considered before intralesional resection to limit intraoperative bleeding. Treatment plans must be guided by lesion characteristics and clinical presentation.

Aneurysmal bone cysts: do simple treatments work?

BACKGROUND

Primary aneurysmal bone cysts (ABCs) are benign, expansile bone lesions commonly treated with aggressive curettage with or without adjuvants such as cryotherapy, methacrylate cement, or phenol. It has been reported that occasionally these lesions heal spontaneously or after a pathologic fracture, and we observed that some ABCs treated at our center healed after biopsy alone. Because of this, we introduced a novel biopsy technique we call "curopsy," which is a percutaneous limited curettage at the time of biopsy, obtaining the lining membrane from various quadrants of the cyst leading to consolidation (curopsy = biopsy with intention to cure).

QUESTIONS/PURPOSES

We asked whether (1) a curopsy results in comparable likelihood of healing of the ABC compared with more aggressive approaches involving curettage, (2) the two approaches differ in terms of the likelihood of recurrence after treatment, and (3) the two approaches differ in terms of complications after surgery.

METHODS

Between January 1, 1999 and June 30, 2012, 221 patients with a diagnosis of primary ABC were registered in our oncology database. Patients presenting with a pathologic fracture and those seeking a second opinion were excluded. One hundred ninety patients were included in the study. One hundred two (54%) were treated with curopsy and 88 (46%) were treated with curettage after a core needle biopsy. Complete followups were available for 88% (90 of 102) and 93% (80 of 88) of patients in those groups, respectively. During that period, a curopsy was performed for all patients with benign bone lesions with imaging suggestive of classic primary ABCs and for whom the core needle biopsy simply showed blood with no solid component. Curettage after a core needle biopsy was reserved for histologically confirmed primary ABCs, lesions with impending fractures, large lesions, if the ABC was thought to be a secondary disorder, and patients for whom the curopsy failed. All patients were followed up until consolidation of the lesion (mean, 9.6 weeks, range, 3-25 weeks, 95% CI, 8.32-10.9 for curopsy; mean, 11.4 weeks, range, 8-32 weeks, 95% CI, 10.6-12.3 for curettage). The median followup for all patients was 14 months (range, 6-36 months).

RESULTS

Of the 102 patients who had curopsy and observation, 83 (81%) required no additional treatment and the lesion resolved. Of the 88 patients who underwent curettage (with or without adjuvant therapy) after core needle biopsy, the success rate was 90% (79 of 88). Local recurrences in both groups (curopsy or curettage) were treated successfully with additional curettage in all but one case. Curopsy in comparison to curettage provided a mean shorter healing time (9.6 versus 11.4, p = 0.01) but there was a higher local recurrence and need for additional intervention rate (18.6% versus 10.2%, p = 0.04). There were no differences in the complications between the treatment groups.

CONCLUSIONS

A curopsy is a novel biopsy technique that was successful in resolving ABCs in 81% of the patients in our study. Curopsy, as a biopsy technique, for ABCs needs consideration as it potentially minimizes the number of patients needing a second procedure (a core needle biopsy being the first) as is the current practice. Furthermore, it does not disadvantage the patient or surgeon should additional intervention be needed in the form of curettage with or without adjuvants.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Functional outcomes and quality of life following surgical treatment of aneurysmal bone cysts of the pelvis in children

BACKGROUND

Aneurysmal bone cysts (ABCs) are a benign aggressive tumor that occurs rarely in the pelvis in the pediatric population. Pelvic ABCs may involve the triradiate cartilage and/or the acetabulum, which increases the technical difficulty of surgical treatment and has potential implications on the growth and development of the hip joint. This study examines the clinical presentation, rate of surgical complications, and recurrence rate, as well as, long-term clinical and functional outcomes of children with pelvic ABCs treated at a single institution by a single treatment modality.

METHODS

Between 1988 and 2008, 142 children with histologically confirmed ABCs were treated at our institution. Seventeen (12 %) tumors were located in the pelvis. A total of 13 pelvic ABCs (5 ilium-periacetabular, 4 pubic, 3 ilium-iliac wing, and 1 ischium) were included in this study. There were eight male and five female patients with a mean age of 12.9 years (range 4.1-17.5 years) at the time of surgery. The Toronto Extremity Salvage Score (TESS), the Musculoskeletal Tumor Society 1993 (MSTS'93) score, and the Short Form Health Survey Sf-36 were obtained at a minimum 5-year follow-up in all patients (mean follow-up 11.5 years, range 5.5-19.8 years). The mean age at follow-up was 24.3 years (range 14.6-32.6 years).

RESULTS

All patients were treated surgically with intralesional curettage extended with a high-speed burr and bone grafting. Eight patients received adjunctive therapy with phenol. Five patients had preoperative selective arterial embolization. Of the 13 patients, 1 had a local recurrence diagnosed at 6 months after surgery. The only complication in the cohort was a superficial wound infection. At the latest follow-up, all patients were free of disease. The mean TESS score was 95 and the mean MSTS'93 score was 93 %. The mean self-rated general health score, according to the SF-36 was 87 % of total points possible.

CONCLUSIONS

Extended curettage and bone grafting of pelvic ABCs in the pediatric population can yield high clinical and functional scores at an average of 11 years follow-up with a low rate of complications and recurrence.

LEVEL OF EVIDENCE

IV, case series.

Aneurysmal bone cyst in the middle turbinate: a case report

Aneurysmal bone cyst is a benign and locally destructive bone lesion usually seen in the younger population. Its etiology is unknown. Its yearly incidence rate has been reported to be 0.14/100,000, comprising 1% of all bone tumors. It may develop primarily or arise from primary bone tumors. Hemorrhagic fluid content with a septated appearance is the characteristic feature of aneurysmal bone cyst. It is most commonly seen in the metaphysis of the long bones. In rare cases, the cyst is located in the skull. Primary treatment is surgical excision, and the recurrence rate after treatment is 10 to 30%. Based on a review of the current literature, there have been no previous reports of aneurysmal bone cyst located in the middle turbinate. We report a case of aneurysmal bone cyst with an atypical location and discuss the treatment of the patient with endoscopic surgery in light of relevant literature.

Benign bone tumors

Benign bone lesions are a broad category that demonstrates a spectrum of activities from latent to aggressive. Differentiating the various tumors is important in order to properly determine necessary intervention. This chapter focuses on the presentation, imaging, diagnostic features, and treatment of the most common benign bone tumors in order to help guide diagnosis and management.

Bipolar electric cauterization as adjuvant treatment after curettage of aneurysmal bone cysts of the hand

Almost all aneurysmal bone cysts of the hand were managed with either simple curettage plus or minus bone graft or en block excision and autograft reconstruction. The high recurrence rate is a major disadvantage of the former technique, whereas complexity/donor-site morbidities are known disadvantages of the latter technique. In the long bones of the lower limbs, adjuvant therapy after curettage is known to reduce the recurrence rate. This article introduces adjuvant bipolar electrical cauterization after curettage of aneurysmal bone cysts of the hands. This technique was used in 6 cases including 1 case with a recurrent lesion after curettage done elsewhere. Complications have been minimal and there was no recurrence at a mean follow-up of 3 years. Although the number of cases in this series is small, the favorable results warrant trying the technique in a multicenter comparative study.

Percutaneous doxycycline treatment of aneurysmal bone cysts with low recurrence rate: a preliminary report

BACKGROUND

Aneurysmal bone cyst (ABC) has a recurrence rate of between 12% and 71% without en bloc resection or amputation. There is no percutaneous ABC treatment drug regimen demonstrating consistent evidence of bone healing with recurrence of < 12%. Doxycycline has properties that may make it appropriate for percutaneous treatment.

QUESTIONS/PURPOSES

We therefore asked: (1) Is there reduction in ABC lytic cyst volume with injectable doxycycline? (2) Is it associated with thickening of involved bony cortex? (3) Is the recurrence rate after percutaneous treatment < 12%?

METHODS

We retrospectively reviewed 20 patients who underwent percutaneous treatment of ABCs with doxycycline from 2006 to 2010. The mean age was 10 years (range, 3-18 years). There were 21 treatment locations: humerus (six), spine (five), clavicle (two), fibula (one), femur (two), ulna (two), tibia (two), and scapula (one). Twenty patients completed treatment involving 118 treatment sessions (two to 14 sessions per patient). Treatment response was evaluated radiographically by measuring the lytic component and thickness of involved cortex. Recurrence was indicated by new areas of lytic destruction after completion of treatment. The minimum followup was 24 months (mean, 38 months).

RESULTS

Twenty of 20 patients demonstrated reduction in lytic destruction and bony healing. All patients demonstrated cortical thickening. One patient demonstrated recurrent minimal lytic destruction after 20 months of observation.

CONCLUSIONS

In this series, patients undergoing percutaneous doxycycline treatment of ABCs demonstrated a healing response and a recurrence rate of 5% at more than 24 months.

A comparison of cyst wall curettage and en bloc excision in the treatment of aneurysmal bone cysts

BACKGROUND

The recurrence rate after aneurysmal bone cyst (ABC) treatment is quite high despite its benign nature. In ABC therapy, curettage is the treatment of choice; en bloc excision results in a lower recurrence rate, but more extensive reconstructive surgery is needed with associated morbidity. The aim of the present study was to compare the outcomes of the two treatment options.

METHODS

A retrospective analysis was performed on 26 patients treated for ABCs: 16 by curettage and 10 by en bloc excision. Each lesion was classified according to Enneking and patients were followed up for a mean time of 9.2 years. On follow-up, radiological examination and functional assessment (range of motion, muscle strength) were performed. Recurrence was defined as the presence of an osteolytic lesion, especially one with a tendency to grow.

RESULTS

On follow-up, the following symptoms were more prevalent in the en bloc excision group compared to the curettage group: pain (en bloc 20% versus curettage 6.25%), limb length differences (en bloc 20% versus curettage 12.5%), reduced range of motion (en bloc 20% versus curettage 6.25%) and muscle strength impairment (en bloc 50% versus curettage 31.2%); however, the differences were not statistically significant (P >0.05). In the curettage group, two cases of postoperative complications and two cases of recurrence were seen, while in the en bloc excision group one case of complications was noted.

CONCLUSIONS

Curettage is a standard procedure in ABC management. En bloc excision is another option, albeit more technically demanding, that may be considered in recurrent lesions with extensive bone destruction or for cysts in an expendable location.

Percutaneous curettage and suction for pediatric extremity aneurysmal bone cysts: is it adequate?

BACKGROUND

The purpose of our study was to evaluate the effectiveness of treating extremity aneurysmal bone cysts (ABC) by percutaneous curettage compared with open intralesional excision.

METHODS

A retrospective review of 17 patients with histologically proven primary ABCs and no evidence of a secondary lesion treated either by percutaneous curettage or open intralesional excision with at least 24-month follow-up was undertaken. The percutaneous curettage group was uniformly treated on an outpatient basis using angled curettes under image guidance followed by intralesional evacuation. The primary outcome was radiographic healing using the Neer/Cole 4-grade classification. Complications were noted.

RESULTS

Seventeen patients with a mean age of 11.7 years (range, 1.7 to 17.5) were evaluated. Nine patients underwent percutaneous curettage and 8 had an open intralesional excision. The 2 treatment groups were comparable with regard to age, sex, number of procedures, morphologic type of ABC, and follow-up period. At follow-up, the proportion of patients with satisfactory healing (Neer/Cole grades I and II) were similar among the 2 groups (P = 0.74). In the percutaneous curettage group, 2 cases recurred necessitating repeat procedures, whereas 1 case recurred in the open intralesional excision group and was successfully treated percutaneously.

CONCLUSIONS

Percutaneous curettage is a safe and minimally invasive alternative for extremity ABCs that can be performed as an outpatient procedure. Not all ABCs require wide exposure and an open intralesional excision.

LEVEL OF EVIDENCE

III.

Enchondroma with secondary aneurysmal bone cyst

An enchondroma with complex cystic changes of the proximal femur is described in a 13-year-old male. The case illustrates a unique presentation of an enchondroma and reinforces the importance of considering the presence of secondary aneurysmal bone cysts in both benign and malignant lesions of bone.

Treatment of a large aneurysmal bone cyst in a 15-year-old boy using a corticospongial bone graft and a 12-year follow-up after operation

We report the case of a 15-year-old boy with a large aneurysmal bone cyst in the third metacarpal, which was operated on radically with excision of the bone and grafting from the distal radius. At 12-year follow-up the patient had good cosmetic results and a perfectly functioning hand.

Aneurysmal bone cyst

Aneurysmal bone cysts are rare skeletal tumors that most 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 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 or without adjuvant treatment. Other management options include cryotherapy, sclerotherapy, radionuclide ablation, and en bloc resection. The recurrence rate is low after appropriate treatment; however, more than one procedure may be required to completely eradicate the lesion.

An aggressive aneurysmal bone cyst of the proximal humerus and related complications in a pediatric patient

Clinical behavior of aneurysmal bone cyst (ABC) in younger patients can be more aggressive than that in older children and adults. Angular deformity and shortening can occur due to growth plate destruction or tumor resection. A 11-year-old boy who had been operated twice in another center for an ABC located in the left proximal humerus presented to the author's institution with complaints of pain, deformity and shortening of the left arm. Plain radiographs revealed left proximal humerus nonunion with a large defect. Reconstruction with nonvascularized fibular autograft was applied and left upper extremity was immobilized in a velpou bandage. At the third-month follow-up, graft incorporation was observed in the distal part; however, proximal part did not show adequate healing on radiographs. Additional immobilization in a sling for 3 months was advised to the patient and his family. However, they were lost to follow-up and readmitted to the author's institution at the 12th month postoperatively. Radiographs showed failure of the fibular graft fixation and nonunion of the humerus. Autogenic bone grafts, either vascularized or nonvascularized are the best treatment method for the large defects after tumor curettage or resection. Nonvascularized grafts are technically much easier to use than vascularized grafts and provide excellent structural bone support at the recipient side. However, they may take several months to be fully incorporated. In addition, good therapeutic outcomes require patience and collaboration with the patient and parents. Most importantly, the patient should be monitored closely.

Factors associated with recurrence of primary aneurysmal bone cysts: is argon beam coagulation an effective adjuvant treatment?

BACKGROUND

Our goal was to assess the effectiveness and safety of argon beam coagulation as an adjuvant treatment for primary aneurysmal bone cysts, to reevaluate the adjuvant effectiveness of the use of a high-speed burr alone, and, secondarily, to identify predictors of aneurysmal bone cyst recurrence.

METHODS

We retrospectively reviewed the records of ninety-six patients with primary aneurysmal bone cysts who were managed at our institution from January 1, 1983, to December 31, 2008. Forty patients were managed with curettage, a high-speed burr, and argon beam coagulation; thirty-four were managed with curettage and a high-speed burr without argon beam coagulation; and the remaining twenty-two were managed with curettage with argon beam coagulation alone, curettage with no adjuvant treatment, or resection of the entire lesion. Demographic, clinical, and radiographic data were viewed comparatively for possible predictors of recurrence. Kaplan-Meier survival analysis with a log-rank test was performed to measure association and effectiveness.

RESULTS

The median age at the time of diagnosis was fifteen years (range, one to sixty-two years). The median duration of follow-up was 29.5 months (range, zero to 300 months). The overall rate of recurrence of aneurysmal bone cyst after surgical treatment was 11.5%. The rate of recurrence was 20.6% after curettage and high-speed-burr treatment alone and 7.5% after curettage and high-speed-burr treatment plus argon beam coagulation. The five-year Kaplan-Meier survival estimate was 92% for patients managed with curettage and adjuvant treatment with a high-speed burr and argon beam coagulation, compared with 73% for patients managed with curettage and a high-speed burr only (p = 0.060).

CONCLUSIONS

Surgical treatment of aneurysmal bone cyst with curettage and adjuvant argon beam coagulation is effective. Postoperative fracture appears to be a common complication of this treatment and needs to be studied further. Treatment with curettage and high-speed burr alone may not reduce recurrence.

Advance in the treatment of aneurysmal bone cyst of the sacrum

OBJECTIVE

The objective of this study was the review of 11 patients with two different treatment methods used historically for aneurysmal bone cyst in the sacrum. The outcome of both procedures is reported. In addition, the treatment technique of CT-guided percutaneous injections of demineralized bone matrix mixed with bone marrow concentrate is described.

MATERIALS AND METHODS

From 1997 to 2008, 11 patients with sacral aneurysmal bone cyst were treated at the Rizzoli Institute, Bologna, Italy. The first seven patients had surgical curettage without bone grafting, chemical adjuvants, or arterial embolization. The last four patients had arterial embolization. The last patient did not respond to arterial embolization and was treated by CT-guided injection of demineralized bone matrix mixed with bone marrow concentrate.

RESULTS

Curettage was successful in five out of seven patients. Two patients suffered complications, and two cases had recurrence. Arterial embolization was successful in three of four patients. The patient treated with injection had a good clinical and radiographic result.

CONCLUSION

Both surgical and arterial embolization are effective for aneurysmal bone cyst in the sacrum. However, these treatments may lead to complications and recurrence. The use of CT-guided injections of demineralized bone matrix mixed with bone marrow concentrate may be a safe and effective alternative for treatment of these destructive and problematic lesions.

Expansile aneurysmal bone cyst in the tubular bones of the hand treated with en bloc excision and autograft reconstruction: a report of 12 cases

Primary aneurysmal bone cysts (ABCs) in the small tubular bones of the hands are rare and optimal treatment is not yet established. Between August 1997 and June 2009, 12 patients with biopsy-proven expansile primary ABCs of the small tubular bones of the hand were treated with en bloc tumor excision and strut autograft reconstruction. The adjacent joint was preserved if feasible, otherwise it was fused. Patients were followed for at least 2 years (mean = 7 years). All grafts were incorporated except for partial resorption in one. There was only one tumor recurrence about 1 year after the operation. Other complications included premature physeal arrest in one case and limitation of adjacent joint motion in three. A relatively low rate of recurrence and other complications indicates that this technique would serve as a good strategy for patients with expansile ABCs in the hand in terms of safety, simplicity and reduced number of re-operations.

Benign bony and soft tissue tumors of the hand

It is important to be familiar with the wide variety of benign tumors that may present in everyday hand surgery practice. The treatment of many of these tumors in the hand is based on studies with small numbers of patients or the treatment of similar lesions elsewhere in the body. The purpose of this review is to summarize the recent literature relevant to benign bony and soft tissue tumors in the hand.

Is sclerotherapy better than intralesional excision for treating aneurysmal bone cysts?

BACKGROUND

Minimally invasive approaches such as sclerotherapy have been introduced to treat aneurysmal bone cysts. Sclerotherapy has been associated with reasonable healing rates during the past two decades. However, it is unclear whether sclerotherapy compares with the more traditional extended curettage and bone grafting.

QUESTIONS/PURPOSES

We therefore compared the healing rates and functional scores in patients having percutaneous repetitive sclerotherapy using polidocanol (Group 1) with those with intralesional excision (extended curettage with a high-speed burr) and bone grafting (Group 2) for treatment of aneurysmal bone cyst.

PATIENTS AND METHODS

We randomly divided 94 patients into two treatment groups. We assessed healing rates (primary outcome measure), pain relief, time to healing and recurrence, hospital stay, and the Enneking functional score. Forty-five patients from Group 1 and 46 from Group 2 were available for study. The minimum followup was 3.2 years (mean, 4.4 years; range, 3.2-6.1 years).

RESULTS

At last followup, 93.3% in Group 1 and 84.8% in Group 2 had achieved healing. Complications in Group 1 were minor and resolved. In Group 2, three patients had deep infections and five had superficial infections, and two had growth disturbances. Although the healing rates were similar, we found higher rates of clinically important complications, worse functional outcomes, and higher hospital burden associated with intralesional excision.

CONCLUSIONS

Repetitive sclerotherapy using polidocanol is a minimally invasive, safer method of treatment for aneurysmal bone cysts compared with intralesional excision and bone grafting. In this preliminary study, we found similar recurrence rates for the two treatment methods, however, this will require confirmation in larger studies.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Case report: primary aneurysmal bone cyst of the epiphysis

Aneurysmal bone cysts are benign active or aggressive bone tumors that commonly arise in the long bones, especially the femur, tibia, and humerus and the posterior elements of the spine. Aneurysmal bone cysts affect all age groups but are more common before skeletal maturity (first two decades of life). They usually involve the metaphysis or metadiaphyseal region of long bones. Although juxtaphyseal lesions abutting the growth plate and extending into the epiphysis have been described, there is no report of an aneurysmal bone cyst entirely and primarily located in the epiphysis. We report on a 3-year-old boy who presented with an entirely contained aneurysmal bone cyst to the proximal tibial epiphysis. We discuss the clinical presentation, diagnosis, including imaging and pathology, and treatment. A review of the pertinent literature also is presented.

Histology can be predictive of the clinical course of a primary aneurysmal bone cyst

INTRODUCTION

Aneurysmal bone cyst is a benign lesion occurring in young patients which frequently recurs after treatment. Biopsy is mandatory for the diagnosis of a putative aneurysmal bone cyst as this lesion can be secondary to another underlying process including a malignant bone tumour. The histopathological features of aneurysmal bone cysts have been examined with the goal of finding relevant criteria for predicting favourable evolution or recurrence of the disease.

PATIENTS AND METHODS

Twenty-one biopsies of surgically treated aneurysmal bone cysts, from 21 patients, were analysed. Histomorphometry by two different methods (3,000- and 200-point-counting) and by two observers was performed to quantify the percentage of each tissue type in the cyst (cellular, fibrillar, osteoid). A healing index was developed by calculating a ratio of osteoid and fibrillar material divided by cellular tissue. Biopsies were also examined using two immunostains, cluster of differentiation 68 (CD68) and proliferating cell nuclear antigen (PCNA).

RESULTS

The final outcome was healing for 16 aneurysmal bone cysts (healing group) and recurrence for the five others (recurrence group), after a mean follow-up of 4.43 years. The two groups differed significantly in the proportion of their cellular content and their healing index. The ratio of CD68 negative to CD68 positive cells was also significantly different between the two groups.

CONCLUSION

Biopsy should be considered as a helpful prognostic factor for aneurysmal bone cyst.

Percutaneous radionuclide ablation of axial aneurysmal bone cysts

OBJECTIVE

The purpose of our study was to retrospectively examine the efficacy of intralesional injection of 32P chromic phosphate, a beta-emitting colloidal radiopharmaceutical, in the treatment of aneurysmal bone cysts of the axial skeleton. Five patients with large aneurysmal bone cysts were managed with injection of 32P chromic phosphate into their tumors under CT guidance. With only a single minor complication, all lesions were observed to ossify on follow-up CT, with an average follow up of 2 years.

CONCLUSION

CT-guided injection of axial aneurysmal bone cysts with 32P chromic phosphate leads to excellent local lesion control. In addition, the morbidity associated with this procedure is lower than that associated with surgical or other nonsurgical treatments.

Aneurysmal bone cyst: the role of cryosurgery as local adjuvant treatment

BACKGROUND

Aneurysmal bone cysts (ABCs) are most often treated with intralesional surgery (curettage) and additional bone grafting. There is debate on whether or not to use adjuvant therapy to decrease the local recurrence rate. This study is done to assess the outcome of curettage and cryosurgery as a treatment of ABC.

METHODS

We analyzed 80 consecutive cases of ABC treated with curettage and cryosurgery. Patients were followed minimal 24 months after surgery (average 55 months, range 24-122 months) with physical examination and radiographs. Functional outcome was evaluated using the musculoskeletal tumor society score (MSTS).

RESULTS

The 80 patients were all treated with curettage and cryosurgery. Additional bone grafting was used in 73 patients, osteosynthesis in 12 and spondylodesis in 1 patient. Four local recurrences were found in this study, a recurrence rate of 5%. All local recurrences were treated successfully with curettage and cryosurgery again 7-33 months after the initial surgery. Postoperative one fracture, one wound infection, and three transient nerve palsy occurred. The average MSTS score was 29.2 at follow-up.

CONCLUSIONS

The use of cryosurgery as adjuvant therapy results in a lower local recurrence rate when compared to other publications for the treatment of ABC and excellent functional results.

Argon beam coagulation as adjuvant treatment after curettage of aneurysmal bone cysts: a preliminary study

The optimal treatment of aneurysmal bone cysts remains an area of debate. Curettage, with or without adjuvant therapy, has been advocated for tumors in most locations. To evaluate argon beam coagulation as adjuvant therapy to curettage, we retrospectively analyzed the complication and recurrence rates in 40 consecutive patients with a diagnosis of aneurysmal bone cyst. For our analysis of recurrence, we excluded six of the 40 patients who were lost to followup or had less than 18 months followup; five patients treated with resection also were excluded. Of the remaining 29 patients, 17 were treated with curettage and argon beam coagulation and 12 were treated with curettage with or without phenol. None of the 17 patients treated with curettage and argon beam coagulation had a recurrence, whereas four patients treated without argon beam coagulation had recurrences. There were no differences between patients treated with or without argon beam coagulation regarding frequencies of intraoperative complications, neurovascular injury, or bone graft incorporation. Argon beam coagulation seems to offer favorable control rates when compared with curettage with or without phenol. No complications have been experienced thus far with its use.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Treatment of benign lesions of humerus with resection and non-vascularised, autologous fibular graft

The aim of this study was to analyse the long-term results of surgical en bloc resection and replacement with non-vascularised, autologous fibular graft for the treatment of large benign humeral lesions without fixation. We retrospectively reviewed data of seven females and 13 males with unilateral benign lesions where steroid injection, curettage and bone grafting or pathological fracture failed to restore integrity. Subperiosteal, en bloc resection of the cystic lesion with a margin of the normal bone was performed. The average age of the patients at the time of operation was 11.8 years (range 4-28 years). All patients were skeletally mature at last follow-up. Aneurysmal bone cysts were histologically identified in seven cases, solitary cysts in 11 and fibrous dysplasia in two cases. No recurrence of the pathology, pain, graft fracture or limitation in range of motion was noted. In three patients in whom the cyst was adjacent to the proximal growth plate of the humerus, there was shortening of the bone at the last follow-up examination measuring 2 cm, 4.5 cm and 6 cm, respectively. Two cases had a valgus deformity of 10° and 15°, respectively, which was evident radiographically at the time of last follow-up. The results of en bloc resection with non-vascularised, autologous fibular graft for the treatment of large benign humeral lesions without fixation are encouraging. The risk of associated complications is low. In our opinion this should be the method of choice in the treatment of large, multi-chamber benign bone lesions of the humerus which fail more "conservative" treatment.

Subperiosteal resection of aneurysmal bone cysts of the distal fibula

We describe the treatment by subperiosteal resection of an aneurysmal bone cyst in the distal fibula in eight patients and highlight the role of the periosteum in the regeneration of bone defects. The mean age of the patients was 13.5 years (12 to 17). Seven had an open growth plate. The mean size of the resected specimen was 5.12 cm (3.5 to 8.0). None of the patients received instillation of bone marrow, autogenous bone graft, allograft or any synthetic bone substitutes. All had complete regeneration of the bone defect within three to nine months, with no joint instability or recurrence. The mean length of follow-up was 11.5 years (2 to 18). At the final follow-up there was no difference in the range of movement, alignment or stability of the ankle when compared with the opposite side. The periosteum played a major role in the complete filling of the bone defects and avoided the morbidity of other techniques.

A case of an aneurysmal bone cyst of a metatarsal: review of the differential diagnosis and treatment options

Aneurysmal bone cyst localized to the metatarsus, while not unheard of, is rather uncommon. The differential diagnosis for this lesion can be challenging, particularly in regard to the possibility of the presence of other giant cells containing tumors of bone, such as giant cell tumor, giant cell reparative granuloma, Brown's tumor of hyperparathyroidism, and telangiectatic osteosarcoma. We report a case of an aneurysmal bone cyst localized to the third metatarsal in a 14-year-old girl who presented with limping, progressively worsening local pain, and swelling in her left foot. The differential diagnosis for her condition was extensive. Ultimately, an en bloc resection was undertaken and the defect was replaced with tricortical iliac autograft. Pathological analysis of the resected tissue was consistent with aneurysmal bone cyst. There was complete healing with no sign of recurrence 3 years after the surgery.

LEVEL OF CLINICAL EVIDENCE

4.

Aneurysmal bone cysts recur at juxtaphyseal locations in skeletally immature patients

Aneurysmal bone cysts are associated with a high rate of recurrence. Many aneurysmal bone cysts arise near open physes or articular cartilage in skeletally immature patients. Fear of damaging these structures could cause surgeons to curette the tumors less aggressively. We hypothesized location of an aneurysmal bone cyst in a periarticular or juxtaphyseal location would increase the risk of recurrence. We retrospectively studied 53 patients with aneurysmal bone cysts treated between 1989 and 2004. All patients had primary disease, and all patients underwent curettage of the lesion. Ten patients (18.9%) had local recurrence. Gender, race, and size did not predict recurrence; however 12 years of age or younger was associated with recurrence. Of the 19 juxtaphyseal cysts directly adjacent to an open physis, eight developed recurrence. Of the five periarticular cysts, two developed recurrence. The data suggest the risk of recurrence is highest in pediatric patients with juxtaphyseal or periarticular aneurysmal bone cysts. Meticulous treatment of these cysts is necessary, but we believe an overly aggressive approach that destroys the physis or articular cartilage is not warranted. Preservation of these structures remains a high priority of treatment.

Aneurysmal bone cyst recurrence in children: a review of 56 patients

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign lesions that are usually treated with intralesional procedures. The clinical behavior of ABCs is reported to be more aggressive in younger patients, with high recurrence rates after surgical treatment by several authors. The purpose of this study was to review longitudinally the demographic data and outcome of current surgical techniques in children with ABC treated at a single institution and to determine the possible risk factors for recurrence, which may be detected at initial examination, including age, presenting complaint, and radiological characteristics.

METHODS

The authors performed a retrospective, pediatric population-based (< or =16 years) analysis of 56 cases of ABCs with more than 2 years' follow-up. The subjects were studied and classified on the basis of their age group (< or =5, 5-10, and >10 years of age). The possible risk factors for recurrence were analyzed initially with Student t test and Pearson chi2 test, then a logistic regression analysis model was used for multivariate analysis.

RESULTS

Nine patients were younger than 5 years, 17 were between 5 and 10 years old, and 30 were older than 10 years. The most frequent location of the lesion was the humerus (11 cases) followed by proximal femur and fibula. Curettage was the most common treatment modality followed by resection. Recurrence of the lesion occurred in 5 children in the younger age group and in 4 children in the older age group. The difference in persistence or recurrence rates based on age (< or =5 years) and previous surgery was statistically significant. In addition, we have found no significant implication of physeal contact and size of the lesion on recurrence.

CONCLUSIONS

The recurrence rates of primary ABC seemed to be higher in younger children. Considering the high cure rates with intralesional procedures even after recurrence, we suggest less aggressive intralesional procedures even in patients with mentioned risk factors; however, the patients' family should be informed about the high probability of recurrence.

Aneurysmal bone cyst of the paediatric shoulder girdle: a case series and literature review

Limited research has analysed paediatric shoulder girdle aneurysmal bone cyst management and outcomes. This study analysed locations affected, investigations, treatments and recurrence in children treated at the London Bone Tumour Unit between 1998 and 2004 and in English and French literature between 1956 and 2004. The proximal humerus and clavicle are most frequently affected whereas scapula involvement is rare. Radiographs, computed tomography and MRI are valuable. Sole curettage of clavicle and scapula lesions has low recurrence rates. Proximal humerus lesions recur most frequently. Curettage alone or with cementation are the most appealing treatments but are associated with significant recurrence.

[Orbital aneurysmal bone cyst in a 2-year-old child]

An aneurysmal bone cyst is a rare tumor-like lesion which can affect any part of the skeleton. It is a disease of childhood and adolescence. Reports of its occurrence on the skull base in children are rare. A 22-month-old male patient was admitted to our ENT department with a sudden protrusion of the right eyeball. Radiologically, a cystic, well-defined and contrast enhanced mass on the medial-cranial orbital wall with beginning destruction of the frontal skull base was detected. Histological assessment of a biopsy, which was taken by medial orbitotomy, showed giant-cellular and fibrohistiocytic changes. Definitive histological diagnosis after removal showed an aneurysmal bone cyst. If there is evidence for aggressive, expansive growth, an aneurysmal bone cyst should be included into the ENT-differential diagnosis of orbital tumors. It is not possible to confirm diagnosis from clinical or radiological data. Early biopsy is essential for a reliable diagnosis even if histological assessment is challenging.

Tumours of the hand

Hand tumours of soft-tissue and bony origin are frequently encountered, and clinicians must be able to distinguish typical benign entities from life-threatening or limb-threatening malignant diseases. In this Review, we present a diagnostic approach to hand tumours and describe selected cancers and their treatments. Soft-tissue tumours include ganglion cysts, giant-cell cancers and fibromas of the tendon sheath, epidermal inclusion cysts, lipomas, vascular lesions, peripheral-nerve tumours, skin cancers, and soft-tissue sarcomas. Bony tumours encompass enchondromas, aneurysmal bone cysts, osteoid osteomas, giant-cell lesions of bone, bone sarcomas, and metastases. We look at rates of recurrence and 5-year survival, and recommendations for adjunct chemotherapy and radiotherapy for malignant lesions.

Modern concepts of primary aneurysmal bone cyst

INTRODUCTION

Despite the long experience of radiologists, pathologists and orthopaedists with aneurysmal bone cysts (ABC), there is limited knowledge regarding the cause of the lesion and the optimal treatment. The pathogenesis of ABC remains unclear with theories ranging from a post-traumatic, reactive vascular malformation to genetically predisposed bone tumours. Recent genetic and immunohistochemical studies proposed that primary ABC is a tumour and not a reactive tumour-simulating lesion. The chromosomal analyses and some reported familial cases of this osteolytic bone lesion propose a hereditary factor in a presumably multifactorial pathogenesis.

MATERIALS AND METHODS

The imaging studies, even CT scan and MRI sometimes do not provide clearly diagnostic criteria for the diagnosis of ABC. The radiographically differential diagnosis between ABC and unicameral bone cyst (UBC) is sometimes not clear. Double density fluid level, septation, low signal on T1 images and high intensity on T2 images strongly suggest the bone cyst is an ABC, rather than a UBC.

CONCLUSION

Common methods of treatment vary considerably in the literature. The usual methods of treatment are curettage, resection, intracystic injections and embolization. Biopsy is imperative before any treatment. Ethibloc treatment remains highly controversial. For some authors Ethibloc injection can be recommended as the first-choice treatment excluding spinal lesions. A minimally invasive method by introduction of demineralized bone and autogenous bone marrow is able to promote the self-healing of a primary ABC.