Prevalence of aneurysmal and solitary bone cysts in young patients

Pathological Fractures in Aneurysmal Bone Cysts: A Systematic Review

Background: Aneurysmal bone cysts (ABCs) are osteolytic, non-malignant, vascular lesions of the bone. Pathological fractures can be a manifestation of the ABCs, which occur in about 8% of ABCs. Different treatments have been described in the literature, but, nowadays, an optimal management of the pathological fractures in patients with ABCs is still a matter of debate and there are no standard guidelines for treatment nor any shared indication about the best surgical intervention. The aim of our study is to review the current literature available on this matter exploring and confronting different surgical treatments for pathological fractures in ABC in order to clarify the surgical approach to these patients. Methods: A systematic review of the literature indexed in PubMed, MEDLINE, and Cochrane Library databases was carried out. The Preferred Reporting Items for Systematically Reviews and Meta-Analyses (PRISMA) were followed. Results: A total of 37 articles were relevant and were finally included in the study. In total, we reached a population of 140 patients. Of the 140 patients included in the review, 124 patients (88.6%) underwent curettage surgery, 15 patients (10.7%) underwent en bloc resection surgery. A total of 47% of patients (70) underwent synthesis surgery with a plate, screw, nail, or external fixator. Adjuvant treatments were used in 8.6% of patients (12). Complications involved 20.7% of the patients (29). Conclusions: In conclusion, the treatment of pathological fractures in aneurysmal bone cysts requires careful patient assessment, considering factors such as age, the presence of open growth plates, the location of the lesion, and the surgeon's expertise.

Management of aggressive recurrent thoracic spine aneurysmal bone cyst in a 7-year-old male: A case report and review of the literature

Background

Spinal aneurysmal bone cysts (ABCs) are rare, histologically benign tumors with aggressive behavior, which may cause bone and soft-tissue destruction, particularly affecting neural elements. Management of these tumors, including treatment modalities and follow-up protocols, remains challenging.

Case Description

A 7-year-old boy presented with chest wall pain persisting for two months before admission, accompanied by progressive mono paresis lasting ten days before admission. Myelopathy signs were evident during the examination. Imaging confirmed a multicystic lesion at the T6 level involving the posterior elements of the vertebra, with significant cord compression. Due to deteriorating neurological function, he underwent urgent laminectomy and neural decompression, followed by subtotal tumor resection. Postoperative histopathological examination confirmed the diagnosis of an ABC, and the patient experienced significant neurological recovery. However, after 21 days, the patient was readmitted to the emergency department with severe paraparesis. Magnetic resonance imaging revealed rapid growth of the residual tumor, leading to cord compression. He underwent aggressive total tumor resection, T6 vertebral body corpectomy, and fixation with pedicle screws and cage insertion. Following the second surgery, prompt neurological recovery occurred.

Conclusion

This rare case report emphasizes the importance of a close follow-up protocol for spinal ABCs in the pediatric population. It highlights the challenges in managing these tumors and the need for vigilant monitoring to detect and address rapid recurrences.

As simple as it sounds? The treatment of simple bone cysts in the proximal femur in children and adolescents: Retrospective multicenter EPOS study of 74 patients

Purpose

Simple bone cysts are among the most prevalent benign cystic tumor-like lesions in children. Proximal femoral simple bone cysts may require specific treatment because of increased fracture risk. With limited literature available on this specific localization, consensus regarding optimal treatment is lacking. We present a large international multicenter retrospective cohort study on proximal femoral simple bone cysts.

Methods

All consecutive pediatric patients with proximal femoral simple bone cyst from 10 tertiary referral centers for musculoskeletal oncology were included (2000-2021). Demographics, primary treatment, complications, and re-operations were evaluated. Primary outcomes were time until full weight-bearing and failure-free survival.

Results

Overall, 74 simple bone cyst patients were included (median age 9 years (range = 2-16), 56 (76%) male). Median follow-up was 2.9 years (range = 0.5-21). Index procedure was watchful waiting (n = 6), percutaneous procedure (n = 12), open procedure (n = 50), or osteosynthesis alone (n = 6). Median time until full weight-bearing was 8 weeks (95% confidence interval = 0.1-15.9) for watchful waiting, 9.5 (95% confidence interval = 3.7-15.3) for percutaneous procedure, 11 (95% confidence interval = -0.7 to 13.7) for open procedure, and 6.5 (95% confidence interval = 5.9-16.1) for osteosynthesis alone (p = 0.58). Failure rates were 33%, 58%, 29%, and 0%, respectively (p = 0.069). Overall failure-free survival at 1, 2, and 5 years was 77.8% (95% confidence interval = 68.2-87.4), 69.5% (95% confidence interval = 58.5-80.5), and 62.0% (95% confidence interval = 47.9-76.1), respectively.

Conclusion

A preferred treatment for proximal femoral simple bone cysts remains unclear, with comparable failure rates and times until full weight-bearing. Watchful waiting may be successful in certain cases. If not feasible, osteosynthesis alone can be considered. Treatment goals should be cyst control, minimizing complications and swift return to normal activities. Therefore, an individualized balance should be made between undertreatment, with potentially higher complication risks versus overtreatment, resulting in possible larger interventions and accompanying complications.

Level of evidence

Level IV, retrospective multicentre study.

Use of Surgical Adjuvants Does Not Decrease Recurrence of Aneurysmal Bone Cysts in Surgical Intervention With Pediatric Patients

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign active tumors often requiring intralesional curettage with or without adjuvants. The primary aim of this study was to analyze whether recurrence is influenced by the use of surgical adjuvants in pediatric patients with ABCs. Secondary aims examined recurrence rates based on age, sex, and physeal contact.

METHODS

A retrospective review was performed at a tertiary pediatric hospital from 2004 to 2020. Inclusion criteria consisted of patients treated surgically for histologically confirmed ABCs with a minimum of 6 months follow-up. Patients with treatment for a recurrent tumor or incomplete records were excluded. Patient demographics, location of the lesion, treatment technique, and incidence of recurrence were collected. Statistical analyses were performed using STATA.

RESULTS

There were 129 patients (74 males and 55 females) with a mean age of 11.5 ± 4.1 years and an average follow-up of 29.0 ± 25.4 months. The most common locations for ABCs were the femur and tibia. Of the patients, 53.5% had tumors abutting the physis, 28.7% had no physeal contact, and 17.8% had insufficient imaging to evaluate physeal contact. Surgical adjuvants (high-speed burr, coagulation, liquid nitrogen, and/or hydrogen peroxide) were used in 91 of the 129 cases (70.5%). There was no significant difference in recurrence when comparing those who received an adjuvant and those who did not (25.3% vs 23.7%, P = 1.000). Physeal contact was also not significantly associated with recurrence ( P = 0.146). Finally, patients younger than 6 years old were significantly more likely to have recurrence compared with those 6 years old or older (66.7% vs 21.7%, P = 0.007).

CONCLUSION

Our study found no association between the use of surgical adjuvants and the risk of recurrence after intralesional curettage for ABCs. Although our study did demonstrate that patients 6 years old or younger had an increased rate of recurrence, no significant association was found regarding physeal contact or sex. These data indicate that surgical adjuvant may not affect the recurrence rates of pediatric patients with ABCs.

LEVEL OF EVIDENCE

Level III. This retrospective review compares rates of recurrence based on the choice of surgical adjuvant.

Aneurysmal bone cyst: a review

Aneurysmal bone cyst (ABC) is a benign locally destructive bone neoplasm composed of multi-loculated blood-filled cystic spaces. The most common sites of involvement are the meta-diaphysis of the long bones and posterior elements of the vertebrae. Secondary, ABC-like changes can complicate a variety of other benign and malignant primary bone neoplasms, including giant cell tumor, fibrous dysplasia, and osteosarcoma. About two-third of primary ABCs have a rearrangement of the USP6 gene, which is not present in the ABC-like changes that occur secondary to other primary bone tumors (i.e., secondary ABC). Primary ABC of bone carries a variable but generally high rate of local recurrence. This paper provides an overview of the pathophysiology, clinical presentation, radiographic and pathologic findings, treatment, and prognosis of ABC.

A Review of Pediatric Heel Pain

The objective of this review article is to provide orthopaedic surgeons and general practitioners a reference and guidance for the evaluation and workup of heel pain in pediatric patients. The authors performed a comprehensive literature search to review the etiologies and management of heel pain in patients <18 years of age. Relevant studies in Medline/PubMed and EMBASE were searched from inception to March 3, 2022 using medical subject headings and text words without limitations on language or study type. The initial search utilized the following Boolean operators: (children) AND (heel pain); (pediatric) AND (heel pain). Heel pain in the pediatric population is usually a benign condition. Sever's apophysitis is the most common etiology of heel pain in pediatric patients. Most causes of heel pain in the pediatric population do not require imaging or extensive workup. However, providers must maintain a high index of suspicion for symptoms that could indicate a more severe pathology.

Benign bony tumors of the paranasal sinuses, orbit, and skull base

Benign bony tumors of the skull base and paranasal sinuses are uncommon entities, with an overall higher incidence in males. Benign bony tumors may lead to local expansion with resultant mass effect of potentially critical structures. Some benign bony tumors may undergo malignant transformation. This article reviews the presentation and management of benign bone tumors of the skull base and paranasal sinuses with special consideration to involvement of the adjacent orbit, intracranial and critical neurovascular structures. This review covers tumor incidence, location, gross and histologic appearance as well as radiographic findings, treatment, and recurrence rates. Tumors discussed in this article include osteochondromas, osteomas, osteoid osteomas, aneurysmal bone cysts, fibrous dysplasia, giant cell tumors, cemento-ossifying fibroma, ameloblastic fibro-odontoma, ecchordosis physaliphora, chondromyxoid fibroma, primary chronic osteomyelitis, primary chronic osteomyelitis, osteochondromyxoma, and dense bone islands.

The blood pressure and use of tourniquet are related to local recurrence after intralesional curettage of primary benign bone tumors: a retrospective and hypothesis-generating study

Aims

Intralesional curettage is a commonly used treatment for primary bone tumors. However, local recurrence of tumors after curettage remains a major challenge.

Questions

(1) Is blood pressure related to local recurrence after intralesional curettage for benign or intermediate bone tumors? (2) What’s the impact of tourniquet usage on the risk of recurrence from high blood pressure?

Methods

This retrospective study evaluated patients receiving intralesional curettage for primary bone tumors from January 2011 to January 2015. A total of 411 patients with a minimum five-year follow-up were included for analysis. Demographic and disease-related variables were first assessed in univariable analyses for local recurrence risk. When a yielded p-value was < 0.2, variables were included in multivariable analyses to identify independent risk factors for local recurrence. Patients were then stratified by tourniquet usage (use/non-use), and risk from high blood pressure was evaluated in both subgroups.

Results

At an average follow-up of 6.8 ± 1.0 years, 63 of 411 patients (15.3%) experienced local recurrence. In multivariable analyses, local recurrence was associated with age (OR, 0.96; 95% CI, 0.94–0.99; p = 0.005); tumor type; lesion size (> 5 cm: OR, 3.58; 95% CI, 1.38–9.33; p = 0.009); anatomical site (proximal femur: OR, 2.49; 95% CI, 1.21–5.15; p = 0.014; proximal humerus: OR, 3.34; 95% CI, 1.61–6.92; p = 0.001); and preoperative mean arterial pressure (> 110 mmHg: OR, 2.61; 95% CI, 1.20–5.67; P = 0.015). In subgroup analyses, after adjusting for age, tumor type, lesion size, and anatomical site, tourniquet use modified the preoperative mean arterial pressure - recurrence relationship: when tourniquet was not used, preoperative mean arterial pressure predicted local recurrence (95–110 mmHg, 4.13, 1.42–12.03, p = 0.009; > 110 mmHg, 28.06, 5.27–149.30, p < 0.001); when tourniquet was used, preoperative mean arterial pressure was not related to local recurrence (all p values > 0.05).

Conclusions

A high preoperative blood pressure was related to local recurrence after intralesional curettage for primary bone tumors in our study. Tourniquet usage and controlling blood pressure might be beneficial for reducing local recurrence in patients scheduled to receive intralesional curettage for primary bone tumor treatment.

Level of evidence

Level IV, hypothesis-generating study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05157-4.

Update on aneurysmal bone cyst: pathophysiology, histology, imaging and treatment

Aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare. ABC can involve any bone in the body, and although it has a metaphyseal preference, it can involve any part of a bone and soft tissues. As with any bone tumor, the initial evaluation of ABCs should be done with radiographs followed by magnetic resonance imaging or less frequently computed tomography for further characterization. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. The main differential diagnosis of an ABC in the pediatric population is unicameral bone cyst (UBC) and telangiectatic osteosarcoma, therefore a biopsy is recommended before treatment. The therapeutic options of ABC range from curettage with or without adjuncts such as phenol, liquid nitrogen, argon laser and bone grafting or bone substitutes to more recently employed alternatives such as image-guided sclerotherapy with various sclerosing agents and monoclonal antibodies (e.g., Denosumab).

The Natural History of Benign Bone Tumors of the Extremities in Asymptomatic Children: A Longitudinal Radiographic Study

BACKGROUND

Benign bone tumors are common incidental findings in the pediatric population during radiographic evaluation. Counseling these patients requires reassurance and raises questions about the natural history of these tumors over time. The purpose of this study was to estimate the prevalence and observe the behavior of benign childhood bone tumors in an asymptomatic population.

METHODS

A historical, longitudinal radiographic collection of healthy children was reviewed, which included comprehensive left-sided radiographs of the extremities at yearly intervals. In this study, 262 subjects with 25,555 radiographs were screened for benign bone tumors at a median age of 8 years (range, 0 to 18 years). All potential tumors were reviewed by a multidisciplinary panel, which confirmed the radiographic diagnosis of each lesion, the age at which the lesion first appeared, and the age at which it had resolved. Prevalence rates were calculated using the number of distinct subjects available for each radiographic location and age.

RESULTS

Thirty-five tumors were identified in 33 subjects, including 19 nonossifying fibromas, 8 enostoses, 6 osteochondromas, and 2 enchondromas. The prevalence rate for all tumors combined increased with age and was 18.9% overall. The overall prevalence rates for specific tumor types were 7.5% for nonossifying fibromas, 5.2% for enostoses, 4.5% for osteochondromas, and 1.8% for enchondromas. Nonossifying fibromas demonstrated a bimodal distribution of prevalence, with a peak at 5 years (10.8%) and another after skeletal maturity (13.3%). The median age at the first appearance for all tumors combined was 9 years (range, 2 to 15 years), but varied by tumor type. Nonossifying fibromas often resolved (7 [37%] of 19), with further resolution possible beyond the last available radiograph. Enostoses, osteochondromas, and enchondromas persisted until the last available radiographs in all subjects.

CONCLUSIONS

The prevalence of benign childhood bone tumors of the extremities was 18.9% in a historical asymptomatic population. Longitudinal radiographs allowed observation of the timing of the first appearance and the potential for resolution for each tumor type. These findings provide unique evidence to answer many commonly encountered questions when counseling patients and their families on benign bone tumors.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Selective arterial embolization of aneurysmal bone cyst in the pubic bone: A possible primary treatment

Aneurysmal bone cyst is a benign highly vascular lesion that occurs in children. Traditionally ABCs were treated by surgical resection. However, lesions at difficult to access anatomical locations such as the pelvis have higher morbidity when treated surgically. Recently with the advances in endovascular treatment selective arterial embolization became a promising option for primary treatment of ABC. The authors present a case of a 14-year-old female with a pelvic ABC that was successfully treated by selective arterial embolization. Selective arterial embolization is a cost-efficient way of managing ABC especially in cases where surgical treatment carries high risk.

Percutaneous alcohol-based sclerotherapy in aneurysmal bone cyst in children and adolescents

INTRODUCTION

Aneurysmal bone cyst (ABC) is a benign bone lesion of childhood and adolescence. It can be locally aggressive, with risk of fracture. Management is controversial. The aim of the present study was to assess the efficacy, simplicity and tolerance of percutaneous alcohol-bases sclerotherapy in ABC.

HYPOTHESIS

Alcohol-based sclerotherapy for ABC under radiographic control is safe and effective.

MATERIAL AND METHODS

A single-center retrospective study for the period 2008-2016 included all of the 55 ABCs, in 54 patients, confirmed on pathology and treated by alcohol-based sclerotherapy under radiographic control. Mean age at diagnosis was 9.6 years. ABC involved the humerus in 30 cases (54%), tibia in 7 (13%) and femur in 5 (9%). Mean follow-up was 50.9 months (range, 16-117 months). Mean number of applications was 1.7 (range, 1-4). Results were assessed clinically (pain, return to sport, limb length and alignment, revision surgery) and radiologically. The main endpoint was lesion volume reduction. The secondary endpoint was failure, defined by open revision surgery or pain preventing return to a sports activity.

RESULTS

Clinical progression was favorable in 36 patients (67%), and radiological progression in 45 (85%). Only 1 cyst required secondary resection. One patient experienced spontaneously resolving intraoperative bradycardia. Male gender and young age emerged as factors for poorer response.

DISCUSSION

ABC management in children can be made difficult by lesion size, aggressiveness, location, proximity to the growth plate and small bone stock. Alcohol-based sclerotherapy is simple, reliable and effective in childhood ABC, and may be a first-line attitude, avoiding recourse to invasive surgery.

LEVEL OF EVIDENCE

IV, retrospective study.

Pelvic Aneurysmal Bone Cyst in an Adolescent: A Case Report and Literature Review

An aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion. The challenge in managing pelvic ABC arises from its relative inaccessibility and the presence of nearby neurovascular structures. In this report, we present the case of a 14-year-old female with pelvic ABC and describe the symptoms, signs, and radiographic appearance of the ABC, management, and good outcome of non-surgical management by selective trans-arterial embolization. Although challenging, non-surgical management of pelvic ABCs can result in a favorable outcome. In addition, we reviewed the literature regarding the treatment modalities of pelvic ABCs.

Surgical clavicle reconstruction after aneurysmal bone cyst resection in a child: A simple method

The clavicle is an infrequent location for primary tumors in general, and aneurysmal bone cyst (ABC) of the clavicle is particularly rare. The challenge of the functional and esthetic result in the treatment of these lesions in the pediatric population is high when considering the reconstruction of critical bone defects. In this article, we present the case of a seven-year-old boy with an ABC in the middle third of the clavicle, treated by resection and reconstruction with free autograft of the fibula stabilized by using an intramedullary titanium nail. We offer a description of the used technique, considerations about treatment options in children, and a follow-up of more than two-and-a-half years.

Challenges in the Diagnosis and Treatment of Aneurysmal Bone Cyst in Patients with Unusual Features

Objectives

Aneurysmal bone cyst (ABC) is a benign but locally aggressive tumor. It has several challenging features. The aim of this study is to identify challenges in the diagnosis and treatment of ABC especially in patients with unusual features.

Methods

This retrospective study involved medical record review of primary ABC patients with one or more of the following features: unusual clinical presentation with a mass or a pathological fracture especially at an unusual age, rare locations, radiological findings suggesting other diagnoses especially sarcoma, and a nondiagnostic histopathology of biopsy samples.

Results

25 patients (17 males and 8 females) were included. Most patients were either younger than 10 or older than 20 years. 10 patients presented with a mass or a pathological fracture. Unusual locations include the scapula, the olecranon, the hamate, the calcaneus, and the first metatarsal bone. Extension into the epiphysis occurred in 2 patients with proximal fibula and olecranon ABCs. Two separate synchronous cysts existed in the proximal epiphysis and middiaphysis of one humerus. Radiological imaging suggested other primary diagnoses in 8 patients. Core needle biopsy was diagnostic in only 2 of 7 patients. The main treatment was intralesional resection/curettage with bone grafting. Wide resection was performed in 4 patients. Recurrence rate was 28%. Recurrence risk factors included the following: age less than 10 years, male gender, and proximal femur location. Late recurrence occurred in 3/7 patients. One patient with asymptomatic radiological recurrence showed subsequent spontaneous resolution one year later.

Conclusions

This study presented multiple unusual features of ABC including: unusual age, rare locations, and nondiagnostic radiological and histopathological findings. These features can complicate the diagnosis and management. Given these features, especially with pathological fractures, a well-planned incision, the use of frozen section examination, and the application of either external fixation or plate osteosynthesis for fracture fixation can be recommended.

Examination and Management of a 4-Year-Old Following a Femoral Aneurysmal Bone Cyst: A Case Report

PURPOSE

The literature lacks recommendations for postoperative rehabilitation following removal of aneurysmal bone cysts (ABCs). This case report describes the rehabilitation with return to age-appropriate functional activities for a 4-year-old following surgical fixation of a femoral ABC, with emphasis on clinical decision-making in the absence of definitive treatment algorithms.

SUMMARY OF KEY POINTS

The child improved in range of motion, strength, balance, transfers, gait, stair negotiation, and percentile rank on the Test of Gross Motor Development 2.

CONCLUSION

This case is successful outcomes of a 4-year-old girl (GP) following surgical fixation for an ABC.

RECOMMENDATIONS FOR CLINICAL PRACTICE

This case fills a current void in the literature emphasizing clinical decision-making and attainment of GP-specific functional goals. A goal-driven approach incorporating key elements of the International Classification of Function model resulted in successful return to age-appropriate activity following surgical fixation of a femoral fracture due to an ABC.

[Bone cysts-differential diagnosis and therapeutic approach]

The differential diagnosis of cystic lesions of the skeleton is multifarious. Besides patient age, the localization and radiologic morphology provide important information for a closer differentiation. Juvenile and aneurysmal bone cysts represent two frequent entities in growing patients. The fluid content of the cysts helps in distinguishing between juvenile and aneurysmal bone cysts. Whereas juvenile bone cysts contain clear fluid, the content of aneurysmal bone cysts consists of blood combined with solid tissue. With respect to progression, aneurysmal bone cysts show a higher activity than solitary bone cysts. The treatment of juvenile bone cysts usually consists of curettage including filling with bone replacement material. For aneurysmal bone cysts the additional use of adjuvants is recommended. Bone cement is preferably used for filling. It shows favorable properties for prophylaxis of recurrence and facilitates the recognition of relapses. Both juvenile and aneurysmal bone cysts often show recurrences.

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.

Mother's fibula in son's forearm: use of maternal bone grafting for aneurysmal bone cyst not amenable to curettage - a case report with review of literature

It has always been a challenge to reconstruct large bone gaps. The aim of this case report is to highlight the success of homologous maternal bone grafting in a large cystic lesion. A six and half years old boy presented to us with an aneurysmal bone cyst (ABC) of the right radius, not amenable to curettage. We excised the lesion in toto, which created an 11 cm bone loss. Considering the age of the patient, we reconstructed the bone gap with maternal fibular graft. Accordingly, 12 cm of fibular graft was harvested and fashioned to fit into the bone gap. It was fixed with an intramedullary K-wire. No cancellous graft was used in the procedure. The limb was kept in the above elbow cast till incorporation of the fibula was noted on the radiographs. Six months following surgery the skiagram showed that the fibula was incorporated. Mobilization of the elbow and wrist was started along with strengthening of the forearm muscles. K-wire was removed at nine months. At the latest follow up of 24 months, the fibula is fully incorporated, the child regained full range of motion and strength of elbow. We discuss the techniques adopted in this particular case along with the review of literature.

Aneurysmal femoral neck cyst: Report of a paediatric case and review of literature

The aneurysmal bone cyst (ABC) is a benign tumour of children and young adults. It represents approximately 1-2% of all bone tumours. The ABC may develop on all skeletal bones, but the proximal end of the femur is the most common location. The authors report a ABC femoral neck in a child of 13 years. This location is pretty special. Indeed, the fragility of the femoral neck due partly to the pathology itself and secondarily curettage requires a judicious attitude surgical (excisional curettage + bone graft + screw) to prevent the risk of high local recurrence and pathological fracture.

Predictive characteristic of simple bone cyst treated with curettage and bone grafting

BACKGROUND

The efficiency of treating simple bone cyst (SBC) is low. Depending on the choice of treatment, a positive response occurs in 20 to 80 % of cases. These rates are unacceptable, particularly considering they concern the treatment of benign lesions affecting children. Although cyst curettage is one of the first known ways of treating SBC, no precise qualification criteria exists for this procedure. The aim of our study is to identify which type of cyst may be most effectively treated using curettage with grafting.

METHODS

A retrospective analysis was performed on 24 patients referred to our clinic for SBC treatment. To identify predictive factors, the group of patients who positively responded to treatment (Neer stages I and II, n = 14) were compared with the group in which recurrences occurred (Neer stages III and IV, n = 10).

RESULTS

Significantly fewer patients with lesions located in the humerus (chi(2) = 9.351; p < 0.05) and without pathological facture at the time of diagnosis (p = 0.017) were found in the group with no recurrence. The following radiological parameters were found to vary significantly between groups: cyst area (z = 3.121; p < 0.01), cyst index (z = 2.213; p < 0.05) and cyst diameter ratio (z = 2.202; p < 0.05). In the group with no recurrences, the mean values of these parameters were found to be lower than in group with poor response to treatment. No statistically significant differences regarding age, sex or type of bone graft (p > 0.05) were found. Recurrences were experienced by 10 patients (41.7 %) during the 3-year period after surgery

CONCLUSION

In the group treated with curettage, associations were identified between worse treatment results and the location in the humerus, pathological fractures at the time of diagnosis, large cyst area, large cyst index and large cyst diameter.

Aneurysmal bone cyst in the temporal bone and complete resection with preoperative embolization. A case report

We describe a rare case of aneurysmal bone cysts (ABCs) that occurred in the petrous portion of the temporal bone. The ABCs were treated with preoperative embolization and complete removal of the mass from the adjacent tissue. The technical details suggest that preoperative embolization is a good treatment option for ABCs.

[Benign cystic bone lesions]

BACKGROUND

Bone cysts are benign tumor-like lesions which often present as a fluid-containing cavity in the bone. They can occur in the skeletal bone as solitary or sometimes multiple bone lesions.

OBJECTIVES

This review discusses the diagnostics, radiological appearance and therapeutic strategies of the most important benign cystic bone lesions, such as simple bone cysts, aneurysmal bone cysts, intraosseous ganglia, epidermoid cysts and subchondral cysts. The differential diagnoses with respect to cystoid formations and tumors with cystic components are discussed.

METHOD

A selective literature search was performed taking own experiences into consideration.

RESULTS

These tumor-like lesions can have the radiological appearance of bone tumors but show no autonomic, stimulus-independent growth and can resolve spontaneously. In the majority of cases open biopsy is necessary to confirm the diagnosis. In some cases no surgical intervention is necessary (e.g. do not touch and leave me alone lesions), whereas in other cases the focus of treatment is on the prevention and therapy of pathological fractures as well as prevention of recurrence.

CONCLUSION

Cystic bone formations are among the most commonly occurring non-traumatic bone lesions. To eliminate differential diagnostic unclarity, histological investigation of biopsy material is essential. In terms of surgical intervention there exists a trend towards multimodal therapy mostly based on a meticulous curretage.

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.

Treatment of unicameral bone cyst: systematic review and meta analysis

PURPOSE

Different treatment modalities have been utilized to treat unicameral bone cyst (UBC), but evidence has not been fully described to support one treatment over another and the optimal treatment is controversial. The aim of this quantitative systematic review was to assess the effectiveness of different UBC treatment modalities.

METHODS

We utilized Pubmed to isolate retrospective studies on patients with UBC who received any kind of treatment. The included studies needed to have a minimum sample size of 15 patients, and have provided data on radiographic healing outcome.

RESULTS

Sixty-two articles were selected for the meta-analysis from a total of 463 articles. The cumulative sample size was 3,211 patients with 3,217 UBC, and male to female ratio was 2.2:1. The summary or pool estimate of methylprednisolone acetate (MPA) injection resulted in a healing rate of (77.4 %) that was comparable to bone marrow injection (77.9 %). A higher healing rate was observed with MPA injection when inner wall disruption was performed. The pool estimate of bone marrow with demineralized bone matrix injection was high (98.7 %). UBC healing rate after surgical curettage was comparable whether autograft or allograft was utilized (90 %). UBC treatment with flexible intramedullary nails without curettage provided almost 100% healing rate, while continuous decompression with cannulated screws provided 89 % healing rate. Conservative treatment indicated a healing rate of 64.2, 95 % CI (26.7-101.8).

CONCLUSIONS

Active treatment for UBC provided variable healing rates and the outcomes were favorable relative to conservative treatment. Due to the heterogeneity of the studies and reporting bias, the interpretation of these findings should be handled with caution.

Bone regeneration with plasma-rich-protein following enucleation of traumatic bone cyst

Traumatic bone cyst is an uncommon non-epithelium lined cavity and is seen frequently in young individuals. The lesion occurs more commonly in the mandible, involving the posterior region. It is generally asymptomatic and is diagnosed on routine radiographic examination. The cystic cavity is usually empty and there is scanty material for histological examination. Surgical curettage is usually done and recurrence is rare. A case of traumatic bone cyst occurring in the anterior region of mandible in a young boy is presented. Following surgical intervention, plasma-rich-protein was placed in the cystic cavity. The lesion showed progressive resolution and bone regeneration of the cystic cavity within a short period of time.

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.

An abnormal bone lesion of the scapula in a collegiate basketball player: a case report

OBJECTIVE

To present the case of a bone lesion of the scapula in a collegiate basketball player.

BACKGROUND

A 19-year-old National Collegiate Athletic Association Division I male basketball player presented with pain in the posterior region of the right shoulder. During practice, he was performing a layup when his arm was forced into hyperflexion by a defender. Evaluation revealed a bone lesion involving the scapular spine and base of the acromion.

DIFFERENTIAL DIAGNOSIS

Acromioclavicular joint sprain, subacromial bursitis, subscapular bursitis, humeral head contusion, acromial fracture.

TREATMENT

The patient was treated for 2 months with therapeutic modalities and rehabilitation exercises. Because of persistent pain and the risk of a pathologic fracture, open surgical biopsy and bone grafting were then undertaken.

UNIQUENESS

Most simple bone cysts affect the proximal humerus and femur, whereas our patient's lesion was in the acromial complex.

CONCLUSIONS

Athletic trainers should be alert to the unusual possibility of bone cysts, which are usually identified incidentally when radiographs are obtained for other reasons. Most simple bone cysts are asymptomatic, but a pathologic fracture can occur with trauma.

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.

Successful treatment of aggressive aneurysmal bone cyst of the pelvis with serial embolization

Intralesional surgery is most commonly used for aneurysmal bone cysts. Rarely is en bloc resection used for active, aggressive, recurrent lesions and those located in expendable bones. However, persistence or recurrence of aneurysmal bone cysts is common. The clinical behavior of aneurysmal bone cysts is more aggressive in younger patients. Selective embolization is used as the primary treatment for aneurysmal bone cysts in surgically difficult anatomical locations and as an adjuvant to surgical treatment to reduce intraoperative blood loss and facilitate curettage.This article describes a 3-year-old boy with an aggressive aneurysmal bone cyst of the pelvis involving the right ischiopubic rami that achieved curative treatment with 3 embolizations with N-2-butyl-cyanoacrylate. Biopsy was diagnostic; however, the clinical course was misleading. Twenty days after the first embolization, despite complete occlusion of the feeding vessels, the patient experienced severe pain, increased size of the lesion, and lateral subluxation of the right hip. Based on the imaging and histological diagnosis, intralesional hemorrhage was assumed, and repeat embolization was performed. After the second embolization, the patient experienced perineal skin necrosis from normal vessel embolization; it was treated with wound dressing changes and healed uneventfully. A third embolization was performed because of a persistent lesion. Six years after treatment, the patient was symptom free, and imaging showed complete ossification of the cyst.Selective catheterization and occlusion of the feeding arteries with the appropriate embolic agent provide tumor devascularization, size reduction, pain relief, and induction of new bone formation. Multiple procedures are often necessary, and complications may occur.

Successful treatment of aneurysmal bone cyst of the proximal fibula with embolization

We present an 8-year-old girl with evolution of an aneurysmal bone cyst of the proximal fibula after intralesional surgery, treated successfully with one selective transfemoral embolization with N-2-butyl-cyanoacrylate. By the first 5 days, the patient experienced complete pain relief. Post-embolization imaging follow-up showed progressive homogenous trabecular bone formation and gradual reduction of the size of the lesion. These findings canceled our initial consideration for surgical treatment. Three years after the embolization, healing of the lesion and remodeling of the proximal fibula were observed without evidence of recurrence. Our successful results with excellent response seen 3 years after embolization are in favor and should increase the awareness of surgeons regarding embolization for aneurysmal bone cysts in difficult anatomic locations such as the proximal fibula.

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.

Metachronous aneurysmal bone cyst in a 9-year-old boy: case report and review of the literature

Aneurysmal bone cyst (ABC) is a locally aggressive, benign bone tumor that commonly affects children. Metachronous ABCs are rare, and have been described only three times in the literature. Here we present a fourth case in a 9-year-old boy who presented with an ABC of the scapula; 2½ years later he presented with a tibial ABC. We also review the literature and discuss the pathological and clinical characteristics of this lesion.

Aneurysmal bone cyst of the acromion treated by selective arterial embolization

Aneurysmal bone cysts are rarely located in the scapula and are especially rare in the acromion. We present an 8-year-old boy with a large aneurysmal bone cyst of the acromion that achieved curative treatment with one selective transcatheter arterial embolization. Five years after the procedure, healing of the lesion and remodeling of the acromion was observed without any evidence of recurrence.

An unusual presentation of a simple bone cyst in the scapula

A 38-year-old man presented with pain in the left shoulder following a fall. A rotator cuff tear was suspected but roentgenograms revealed a lytic, expanded, multiseptate lesion of the scapula adjacent to glenoid. This was compatible with a giant cell tumor, aneurysmal bone cyst or simple bone cyst. The MRI showed rim enhancement and clinched the diagnosis of simple bone cyst. An infraspinous approach to scapula was undertaken and open biopsy confirmed the diagnosis of simple bone cyst. Definitive treatment in the form of curettage and calcium phosphate cementation was carried out. The postoperative period was uneventful. Early mobilization was started. Patient remained well on follow-up and has returned to work in a physically demanding capacity.

Steroid hormone metabolizing enzymes in benign and malignant human bone tumors

IMPORTANCE IN THE FIELD: Primary bone tumors are considered as (sex steroid) hormone-dependent tumors. Osteosarcoma, osteoblastoma and bone cysts are preferentially found in males, while giant cell tumors are more common in females. Indeed, bone tumor development and progression are influenced by sex steroid hormones derived from in situ synthesis in bone cells.

AREAS COVERED IN THIS REVIEW

This review describes intracrine mechanisms for local formation of the biologically most active estrogen, 17beta-estradiol (E2), from circulating steroid precursors through the 'aromatase' (aromatization of androgens) and the 'sulfatase' (conversion of inactive estrone-sulfate) pathway.

WHAT THE READER WILL GAIN

The reader gains knowledge on both pathways and the enzymes, which contribute to the in situ availability of active hormones, namely 3beta-hydroxysteroid dehydrogenases, 17beta-hydroxysteroid dehydrogenases, aromatase, steroid sulfatases and sulfotransferases. An overview is given and the expression and function of these enzymes in bone tumors are discussed.

TAKE HOME MESSAGE

Knowledge on pathways for the in situ formation of E2 in bone cells may allow the identification of potential targets for i) novel endocrine therapeutic options in primary bone tumors and ii) future preventive interventions.

Successful treatment of aneurysmal bone cyst of the hip in a child by selective transcatheter arterial embolization

Aneurysmal bone cysts are rare lesions that occur more commonly in the first and second decades of life. In children, a juxtaepiphyseal location is associated with increased risk of growth plate damage, skeletal deformity, and recurrence. Different treatments have been reported for the management of aneurysmal bone cysts, including surgical excision with or without adjuvants, intralesional injection of sclerosing agents, radiation therapy, cryotherapy, systemic calcitonin therapy, and selective arterial embolization. The authors present the case of a 5-year-old girl with a large aneurysmal bone cyst at the proximal femur, complicated by a pathologic fracture; treatment with two selective transcatheter arterial embolizations was curative.

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.

Active unicameral bone cysts in the upper limb are at greater risk of fracture

PURPOSE

To elucidate the natural history of unicameral bone cyst (UBC) and risk factors for pathological fracture.

METHODS

14 males and 8 females (mean age, 9 years) diagnosed with UBC were reviewed. Cyst location, symptoms, and whether there was any fracture or surgery were recorded. Cyst parameters were measured on radiographs, and included (1) the cyst index, (2) the ratio of the widest cyst diameter to the growth plate diameter, and (3) the adjusted distance of the cyst border from the growth plate.

RESULTS

There were 11 upper- and 11 lower-limb cysts. 13 patients had pathological fractures and 9 did not. 20 patients were treated conservatively with limb immobilisation; 2 underwent curettage and bone grafting (one resolved and one did not). Seven cysts resolved (5 had fractures and 2 did not). The risk of fracture was higher in the upper than lower limbs (100% vs 18%, p<0.001). Fractured cysts were larger than unfractured cysts (mean cyst index, 4.5 vs. 2.2, p=0.07). Active cysts were more likely to fracture.

CONCLUSION

Conservative management had a 30% resolution rate. Surgery should be considered for large active cysts in the upper limbs in order to minimise the fracture risk.

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.

A comparative study of simple bone cysts of the jaw and extracranial bones

OBJECTIVES

To improve the interpretation of simple bone cyst (SBC) lesions of the jaw.

METHODS

A comparative study of SBC lesions of the jaw and extracranial bones was performed through a literature survey.

RESULTS

In extracranial SBC, the cavities were always filled with fluid, and a high recurrence rate was shown through extensive research. Aneurysmal bone cyst (ABC) was included in the differential diagnosis owing to some clinicopathologic similarities. Fluid, gas and blood were found in the cavity in jawbone SBC, and recurrence was believed to be rare. Differential diagnosis was rarely discussed in the literature.

CONCLUSIONS

Based on reports, the cavity did not normally contain gas because no air-fluid level was observed on panoramic radiographs and no density/intensity area indicating gas was seen on CT or MRI. A blood-filled cavity should be examined carefully, and the possibility of an ABC should be considered. The recurrence rate needs to be re-estimated because an extensive survey has not been performed to clarify the treatment outcomes of jawbone SBC.

Estrogen sulfotransferase (SULT1E1) expression in benign and malignant human bone tumors

BACKGROUND AND OBJECTIVES

17beta-estradiol regulates growth and differentiation in normal and malignant bone. E2 is inactivated to 17beta-estradiol-sulfate through estrogen sulfotransferase (SULT1E1).

RESULTS

In an explorative study, SULT1E1 mRNA expression was assessed in a broad range of samples from benign, primary and secondary malignant bone tumors. We detected SULT1E1 mRNA in 31/50 tumor samples (10/19 malignant, 6/13 benign tumors; 15/18 metastases). Significantly more SULT1E1-positive samples were found in metastases than in primary bone tumors (P = 0.019). Yet, there was no difference between malignant and benign primary tumors (P = 0.718). SULT1E1 mRNA levels were not related to patients' age, gender, tumor location, stage, grading, and chemotherapy pretreatment. Relative SULT1E1 mRNA levels did not correlate with that of estrogen-receptor alpha (ERalpha) as assessed by quantitative TaqMan PCR (10 malignant, 8 benign tissue samples). In the latter, ERalpha mRNA, but not SULT1E1 mRNA levels were significantly lower than in the malignant samples (P = 0.006 and P = 0.71, respectively). Also, pronounced expression of SULT1E1 mRNA but not of ERalpha mRNA was observed in osteosarcoma (MG-63, HOS) and Ewing's sarcoma (TC-71) cells, while human osteoblasts and BMSC contained ERalpha but not SULT1E1 mRNA.

CONCLUSION

Frequent expression of SULT1E1 mRNA in various human bone tumors suggests that sulfonation might be important to control E2 levels and activity.