Aims. Aneurysmal bone cysts (ABCs) are locally aggressive lesions typically found in the long bones of children and adolescents. A variety of management strategies have been reported to be effective in the treatment of these lesions. The purpose of this review was to assess the effectiveness of current strategies for the management of primary ABCs of the long bones. Methods. A systematic review of the published literature was performed to identify all articles relating to the management of primary ABCs. Studies required a minimum 12-month follow-up and case series reporting on under ten participants were not included. Results. A total of 28 articles meeting the eligibility criteria were included in this review, and all but one were retrospective in design. Due to heterogeneity in study design, treatment, and outcome reporting, data synthesis and group comparison was not possible. The most common treatment option reported on was surgical curettage with or without a form of adjuvant therapy, followed by injection-based therapies. Of the 594 patients treated with curettage across 17 studies, 86 (14.4%) failed to heal or experienced a recurrence. Similar outcomes were reported for 57 (14.70%) of the 387 patients treated with injection therapy across 12 studies. Only one study directly compared curettage with injection therapy (polidocanol), randomizing 94 patients into both treatment groups. This study was at risk of bias and provided low-quality evidence of a lack of difference between the two interventions, reporting success rates of 93.3% and 84.8% for injection and surgical treatment groups, respectively. Conclusion. While both surgery and sclerotherapy are widely implemented for treatment of ABCs, there is currently no good quality evidence to support the use of one option over the other. There is a need for prospective multicentre randomized controlled trials (RCTs) on interventions for the treatment of ABCs. Cite this article: Bone Jt Open 2021;2(2):125–133

Introduction. Aneurysmal bone cysts commonly found in lower limbs are locally aggressive masses that can lead to bony erosion, instability and fractures. This has major implications in the lower limbs especially in paediatric patients, with potential growth disturbance and deformity. In this case series we describe radical aneurysmal bone cyst resection and lower limb reconstruction using cable transport and syndesmosis preservation. Materials & Methods. Case 1 - A 12-year-old boy presented with a two-week history of atraumatic right ankle pain. An X-ray demonstrated a distal tibia metaphyseal cyst confirmed on biopsy as an aneurysmal bone cyst. The cyst expanded on interval X-rays from 5.5cm to 8.5cm in 9 weeks. A wide-margin en-bloc resection was performed leaving a 13.8cm tibial defect. A cable transport hexapod frame and a proximal tibial osteotomy was performed, with syndesmosis screw fixation. The transport phase lasted 11 months. While in frame, the boy sustained a distal femur fracture from a fall. The femur and the docking site were plated at the same sitting and frame removed. At one-year post-frame removal he is pain-free, with full ankle dorsiflexion but plantarflexion limited to 25 degrees. He has begun graduated return to sport. Results. Case 2 - A 12-year-old girl was referred with a three-month history of lateral left ankle swelling. X-ray demonstrated an aneurysmal bone cyst in the distal fibula metaphysis. The cyst grew from 4.2 × 2.3cm to 5.2 × 3.32cm in 2 months. A distal fibula resection (6.2cm) with syndesmosis fixation and hexapod cable transport frame were undertaken. The frame was in situ for 13 weeks and during this time she required an additional osteotomy for premature consolidation and had one pin site infection. After 13 weeks a second syndesmosis screw was placed, frame removed, and a cast applied. 3 months later she had fibular plating, BMAC and autologous iliac crest bone graft for slow union. At 3 years post-operative she has no evidence of recurrence, is pain-free and has no functional limitation. Conclusions. We describe two cases of ankle syndesmosis preservation using cable transport for juxta-articular aneurysmal bone cysts. This allows wide resection to prevent recurrence while also preserving primary ankle stability and leg length in children. Both children had a minor complication, but both had an excellent final outcome. Cable bone transport and prophylactic syndesmosis stabilization allows treatment of challenging juxta-articular aneurysmal bone cysts about the ankle. These techniques are especially useful in large bone defects

Aim: To evaluate the role of selective arterial embolization of Aneurysmal Bone Cyst of the mobile spine (C1-L5). Ten to 35% of aneurysmal bone cyst arises from the mobile spine. The course of the disease depends on the aggressiveness of the tumor, as well as the treatment. No previous series analyses this aspect. Methods: Fourteen cases of Aneurysmal Bone Cyst of the mobile spine were retrospectively reviewed. All charts, radiographs, and images were reviewed allowed for oncologic and surgical staging of these cases. The mean follow-up was 3,5 years (2,5y Ð 11y) and the mean age at diagnosis was 22 years. Lumbar and cervical spine was more frequently involved (5 cases cervical and 5 lumbar). Histologic diagnosis was obtained in all cases. A slow and gradual onset of pain was the constant symptom. In all cases an arterial study was performed and in thirteen cases a selective arterial embolization (SAE) was performed. Six of them were repeated Results:Only two patients shows complete ossiþcation of the cyst without surgery (T10 and T1) and was curative. All the others patients received surgical treatment (curettage or en bloc excision) In three of them a recurrence of disease was diagnosed 6, 8 and 12 months later. Two of the most recent cases shows a little lityc area without symptoms Conclusions: Selective arterial embolization seems NOT be sufþcient to obtain ossiþcation of Aneurysmal Bone Cyst o mobile spine

Purpose: Aneurysmal bone cyst is a benign osteodystrophic pseudotumor. It can occur as a primary lesion or develop on a pre-existing lesion. The etiopathogenesis, diagnosis and treatment remain subjects of interest. Material and methods: For this retrospective analysis, we collected 48 peripheral aneurysmal bone cysts over a 27-year period. Most cysts occurred in children, adolescents, or young adults, with a slight female predominance. Imaging included standard x-rays, computed tomography, and for the more recent cases magnetic resonance imaging (MRI). MRI provided new imaging features increasing diagnostic accuracy. Second readings of histology slides enabled establishment of the correct diagnosis in certain cases but differential diagnosis was established only with benign tumours. Surgical treatment predominated. Other treatments included curettage-filling with cancellous bone, resection, resection-reconstruction,curettage-filling with cement. Adjuvant treatments mainly involved use of calcitonin. Therapeutic abstention with surveillance confirmed the possibility of spontaneous regression after biopsy. Curettage-filling with cancellous bone was performed in 58% of cases, giving an Enneking function score of 95.7%. Results: We reviewed outcome at mean 7 years follow-up. There were four recurrent cysts and the mean global Enneking score was 95%. Our series showed the several methods can be used for the treatment of aneurysmal bone cysts, the indication taking into consideration the patient’s age, the location of the lesion and is progression. We propose a therapeutic schema. The role of calcitonin remains to be determined. Conclusion: The diagnosis of bone cysts requires a close collaboration between the surgeon, the radiologist, and the pathologist. The indication for surgery must be made case by case to achieve cure without sequelae

Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. We previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine. Fourteen patients (6 male, 8 female) were treated between June 2014 and December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12–60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, data suggest that BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

Introduction and Objective. Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. Other emerging treatments for ABCs include bisphosphonates, percutaneous doxycycline, sclerotherapy and Denosumab. In addition, we previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. One of the potential advantages of such a method is that surgical treatments are not necessary, thus allowing for both a minimally invasive approach and the treatment of poorly accessible lesions. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine and followed for at least one year. Materials and Methods. Fourteen patients (6 male, 8 female) were treated between June 2014 to December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12– 60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Results. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. We also observed that five out of six female patients (83.3%) were less than sixteen years old and four of these (66.7%) were managed with a single dose of BMC injection, while a higher percentage of male patients (6/8, 75%) were more than sixteen years old and more than one injection was administered to them. Conclusions. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

The nature of the Aneurysmal Bone Cyst (ABC) is still controversial among benign tumor, often identifiable in the “aggressive” form (Enneking stage 3) or pseudotumoral lesion. It is well known instead the very high risk of intraoperative bleeding, indicating a strongly unfavorable relationship between the surgical morbidity and the nature of the disease. Recently, excellent results have been obtained in the treatment of ABC by repeated arterial embolizations (SAE), without any surgery, while initial experiences with administration of denosumab and doxycycline are still under study. This study presents the results of our initial experience in the treatment of vertebral ABC through the use of concentrated autologous mesenchymal stem cells (MSCs). Two teenagers aged 15 years, male, and 14 years, female, came to our attention both with diagnosis of ABC in C2 vertebra which was histologically confirmed. They were both neurologically intact, the girl complained of neck pain. The arteriography showed in both cases close relationships between the pathological ABC vascularization and the vertebral and cervical ascending arteries, making treatment by selective arterial embolization unsuitable. After discussion with the parents of patients, we jointly decided to undertake the treatment by direct injection of MSCs preceded, in the same operative session, by harvesting from the iliac crest of 60 cc of bone marrow (by needle aspiration) and its separation with the use of concentration system Res-Q ™ 60 BMC. In the second case the treatment was repeated two times at distance of 4 months. The clinical and radiological follow-up is to of 30 months from the first treatment in both cases. In the first case the presence of newly formed bone within the ABC appeared as a clear sign of recovery just a month after the first treatment and increased gradually, until the cyst appeared completely ossified one year after the treatment, with associated disappearance of the pain. In the second case an initial sclerotic peripheral margin appeared after the second treatment and later ossification progressed, concurrently with the disappearance of the pain. Treatment with selective serial arterial embolization is considered effective in the treatment of ABC even if not without risks, mainly related to the frequent and repeated exposure to ionizing radiation. Furthermore, in a certain percentage of cases the procedure is not technically executable, especially for the presence of arteries afferent to the medullar vascularization. Inconsistent results were obtained with other procedures: the injection of calcitonin, steroid, alcoholic solutions, or the use of sclerosing substances. Radiation therapy, though very effective, it is not considered the first choice. Recently, promising results have been achieved by the injection of mononuclear cells derived from bone marrow in the treatment of Aneurysmal Bone Cyst. Based on the early results obtained in the two cases described, the injection of MSCs can be considered a valid alternative in the treatment of vertebral ABCs untreatable by embolization

We report a case of an aneurysmal cyst localized in the patella of a 37-year-old man. The lesion was secondary to a chondroblastoma at six years follow-up after initial curettage and bone graft. It were no recurrence. Treatment of aneurysmal cysts depends on the degree of articular involvement. We made a detailed study of 11 cases of this rare localization of aneurysmal cysts reported in the literature.

Purpose. The traditional management of pediatric aneurysmal bone cysts involves the application of intralesional resection principles that are used to treat benign aggressive tumors in general. Alternatively, some are treated by injections of sclerosing agents. The risks of these approaches include growth arrest, additional bony destruction necessitating the restoration of structural integrity, and soft tissue necrosis. We wished to evaluate the effectiveness of treating aneurysmal bone cysts in children by percutaneous curettage as a means to avoid these risks. Method. A retrospective cohort study of pediatric, histologically proven aneurysmal bone cyst patients treated either by percutaneous curettage or by open intralesional resection with two years follow up was undertaken. Those cysts judged as uncontained and requiring restoration of structural bony integrity underwent open intralesional resection and reconstruction. Contained cysts judged as not requiring immediate structural restoration were treated percutaneously. This group was uniformly treated on an outpatient basis using angled curettes under image guidance followed by intralesional evacuation using a suction trap. None in this group had insertion of any substance into the cyst cavity. Short-term casting or immobilization was undertaken in most cases. The primary outcome evaluated was radiographic resolution, persistence or recurrence at two years according to the Neer/Cole classification. Complications were noted. Results. Twenty patients with a mean age of 11 (2–15) were evaluated, with ten in each group. In the open intralesional resection group, 9/10 achieved Neer/Cole grade I resolution; one case recurred and was successfully treated percutaneously. There was one case of valgus proximal tibial overgrowth deformity requiring hemiepiphysiodesis, and three cases requiring hardware removal for irritation. In the percutaneous group, 7/10 achieved Neer/Cole grade 1 resolution, one case exhibited radiographic persistence of nonexpansile, lytic change and two cases frankly recurred, necessitating repeat procedures. No fractures, growth arrests, or infections occurred in either group. Conclusion. Not all aneurysmal bone cysts require wide exposure for intralesional resection. Percutaneous curettage is a reasonable alternative for contained aneurysmal bone cysts. Children will readily restore bone stock in the absence of bone graft or bone substitute as long as the cyst is erradicated. Percutaneous curettage should be performed selectively and on an investigational basis for the time being

Introduction. Aneurysmal bone cysts are uncommon benign lesions affecting the spinal column. They mostly occur in the lumbar spine and have a propensity to affect adjacent vertebrae. We describe 14 aneurysmal bone cysts affecting the spinal column from the Scottish Bone Tumour Registry with regard to assess the incidence, demography, biological behaviour and recurrence rate. Materials and Methods. We identified 14 patients with aneurysmal bone cysts affecting the spinal column. Case notes and radiographs were retrospectively reviewed from the Scottish Bone Tumour registry. Results. There were 9 female and 5 male patients. The mean age at presentation was 24.5 years (range, 6 to 62 years). The spinal location consisted of cervical (3), thoracic (4), lumbar (6) and sacral (1). The treatment included curettage without bone grafting (3), excision (7) and surgical removal with biopsy in rest. Selective angiographic embolisation was carried out in one patient with a cervical cyst and percutaneous sclerotherapy was carried out on another with a sacral cyst. There were two recurrences, of which one was treated with radiotherapy and other with repeat curettage with successful final outcome. Conclusions. The incidence of aneurysmal bone cysts was 5.5% in our registry of all the spine tumours. The recurrence occurred in 14% (2 of 14). In addition to surgery, one should be aware of the role of angiographic embolisation and radiotherapy in selected primary and recurrent ABCs

Aim: The purpose of this study was to describe the prevalence, recurrence rate and disease-free interval of aneurysmal and juvenile bone. Methods: A analysis of 141 cases of cystic bone lesions recorded in the Vienna Bone Tumor Registry between 1970 and 2000 was performed. 73 aneurysmal and 68 juvenile bone cysts were registered. 128 (92%) cases were managed by intralesional curettage and adjunctive chemical cautery with phenol followed by bone grafting. Seven cases (4%) were treated by single curettage, in four cases (2.8%) a marginal enbloc resection was performed and two (1.2%) cases were treated by intracystic injections of methylprednisolone acetate. All patients were followed up for a mean of 36 months (range, seven to 144 months) with frequent clinical and radiological examination. Results: The annual prevalence of aneurysmal bone cyst was between 0 and 1.238 per 105 individuals and for juvenile bone cyst between 0 and 0.963. The median age was 11.1 years (range 1– 19.7 years) with a male to female ratio of 1:1.81 for aneurysmal bone cyst and 10.4 years (range 0.5–19.9 years) and a rate of 1:1.96 for juvenile bone cyst. The cumulative probability of a survival without months after surgery was 0.83 (95% confidence interval, 0.77 to 0.90) for aneurysmal bone cyst and 0.79 (95% confidence interval, 0.69 to 0.90) for juvenile bone cyst. Conclusion: We think that the intralesional curettage with additional phenol induced cautery followed by bone grafting provides excellent results and is a successful and sufficient procedure in the therapy of these non-neoplastic bone lesions

The October 2015 Children’s orthopaedics Roundup. 360 . looks at: Radiographic follow-up of DDH; When the supracondylar goes wrong; Apophyseal avulsion fractures; The ‘pulled elbow’; Surgical treatment of active or aggressive aneurysmal bone cysts in children; Improving stability in supracondylar fractures; Biological reconstruction may be preferable in children’s osteosarcoma; The paediatric hip fracture

The Authors report the early results of endoscopic curettage with bone grafting to treat aneurysmal bone cysts. Four patients with aneurysmal bone cysts (one located in the femur and three in the humerus) received curettage with homologous bank bone grafting by endoscopy. In one case we used homologous bank bone in chips with osteoconductive properties and in three cases we used homologous bank bone in paste with osteo-inductive properties. The follow-up showed complete improvement in pain, new bone formation and remodelling at 2 years. Even if we do not yet have final results about recurrence, these early data encourage us to continue this study so that a longer follow-up will confirm the benefits of this procedure

Spinal surgery deals with the treatment of different pathological conditions of the spine such as tumors, deformities, degenerative disease, infections and traumas. Research in the field of vertebral surgery can be divided into two main areas: 1) research lines transversal to the different branches; 2) specific research lines for the different branches. The transversal lines of research are represented by strategies for the reduction of complications, by the development of minimally invasive surgical techniques, by the development of surgical navigation systems and by the development of increasingly reliable systems for the control of intra-operative monitoring. Instead, specific lines of research are developed within the different branches. In the field of oncological pathology, the current research concerns the development of in vitro models for the study of metastases and research for the study of targeted treatment methods such as electrochemotherapy and mesenchymal stem cells for the treatment of aneurysmal bone cysts. Research in the field of spinal deformities is focused on the development of increasingly minimally invasive methods and systems which, combined with appropriate pharmacological treatments, help reduce trauma, stress and post-operative pain. Scaffolds based on blood clots are also being developed to promote vertebral fusion, a fundamental requirement for improving the outcome of vertebral arthrodesis performed for the treatment of degenerative disc disease. To improve the management and the medical and surgical treatment of vertebral infections, research has focused on the definition of multidisciplinary strategies aimed at identifying the best possible treatment path. Thus, flow-charts have been created which allow to manage the patient suffering from vertebral infection. In addition, dedicated silver-coated surgical instrumentation and bone substitutes have been developed that simultaneously guarantee mechanical stability and reduce the risk of further local infection. In the field of vertebral traumatology, the most recent research studies have focused on the development of methods for the biostimulation of the bone growth in order to obtain, when possible, healing without surgery. Methods have also been developed that allow the minimally invasive percutaneous treatment of fractures by means of vertebral augmentation with PMMA, or more recently with the use of silicone which from a biomechanical point of view has an elastic modulus more similar to that of bone. It is clear that scientific research has changed clinical practice both in terms of medical and surgical management of patients with spinal pathologies. The results obtained stimulate the basic research to achieve even more. For this reason, new lines of research have been undertaken which, in the oncology field, aim at developing increasingly specific therapies against target receptors. Research efforts are also being multiplied to achieve regeneration of the degenerated intervertebral disc and to develop implants with characteristics increasingly similar to those of bone in order to improve mechanical stability and durability over time. Photodynamic therapies are being developed for the treatment of infections in order to reduce the use of antibiotic therapies. Finally, innovative lines of research are being launched to treat and regenerate damaged nerve structures with the goal, still far from today, of making patients with spinal cord injuries to walk

The aim of this study is to assess the long-term results of Ethibloc (Ethnor Laboratories/ Ethicon, Norderstedt, Germany) injection in aneurysmal bone cysts (ABC). 33 patients with aneurysmal bone cysts were treated with computed tomographic (C.T) guided percutaneous injection of Ethibloc into the cyst cavity. 22 patients had Ethibloc injection as primary treatment and 11 patients had presented to us with recurrence following previous procedures including steroid injection, bone marrow injection, curettage bone grafting and various other surgical procedures. The mean follow-up was 54 (22-90) months. Symptoms were relieved in all patients. 2 patients were lost to follow up. 18 (58%) of the 31 patients followed, had complete resolution of the lesion, 11 (35.5%) patients had partial healing (asymptomatic residual non progressive lytic areas). 2 (6.5%) patients showed recurrence in the proximal humerus during the follow-up. They are under follow-up but asymptomatic. 2 patients encountered more significant complications after the procedure. Ethibloc injection is a relatively simple, minimally invasive alternative procedure for the treatment of ABC, and makes open operation unnecessary by stopping the expansion of the cyst and inducing endosteal new bone formation. This technique may be used as the primary management of ABCs excluding spinal lesions as shown by this long-term follow-up study

The June 2014 Oncology Roundup. 360 . looks at: Infection still a problem in endoprosthetic reconstruction; massive allografts not as successful as we perhaps think; curopsy for aneurysmal bone cysts?; lengthening prosthesis: days are numbered; new WHO classification in brief; proximal tumours and fluid levels: bad news; infection is predictable in orthopaedic oncology; psychosocial support key in oncological outcomes

Abstract. Background. Benign osteolytic lesions of bone represent a diverse group of pathological and clinical entities. The aim of this study is to highlight the importance of intraoperative endoscopic assessment of intramedullary osteolytic lesions in view of the rate of complications during the postoperative follow up period. Methods. 69 patients (median age 27 years) with benign osteolytic lesion had been prospectively followed up from December 2017 to December 2018 in a university hospital in Cairo, Egypt and in a level-1 trauma center in United Kingdom. All patients had been treated by curettage with the aid of endoscopy through a standard incision and 2 portals. Histological analysis was confirmed from intraoperative samples analysis. All patients had received bone allografts from different donor sites (iliac crest, fibula, olecranon, etc). None of them received chemo or radiotherapy. Results. Most of lesions were enchondroma (n=29), followed by Aneurysmal bone cyst (ABC) (n=16), Fibrodysplasia (n=13), Chondromyxoid fibroma (n=3), simple bone cyst (n= 3), non-ossifying fibroma (n= 3), giant cell tumour (n= 1) and chondromyxoid fibroma (n = 1). Site of lesion varied from metacarpals (n = 29), femur (n= 1), lower leg (n= 31), and upper limb (n=18). Complications happened only in 9 cases (pathological fractures (n=2), infection (n= 1), recurrence (n=3, all aneurysmal bone cyst), residual pain (n= 3, all in tibia). None of cases developed malignant transformation. Conclusion. Endoscopy is recommended in management of benign osteolytic bone lesions; as it aids in better visualization of the hidden lesions that are missed even after doing apparently satisfactory blind curettage. From our study the recurrence rate is 2% compared to the known 12–18% recurrence rate in the blind technique from literature

Aneurysmal bone cysts are benign lesions of bone that tend to recur if they display an aggressive behaviour. In this study, an aggressive lesion is described as one with almost completely lost cortices on standard x-rays, mimicking ‘vanishing bone disease’. Purpose of this study is to retrospectively analyse the treatment results in this special patient subgroup. Sixteen patients with a mean age of 23.1 (6–44) were included in this study. Femur (%25) was the most commonly affected bone. Spinal lesions were excluded. All lesions were diagnosed by preoperative tru-cut biopsy, however open biopsy was also done if requested by the pathologist. All lesions were preoperatively examined by contrast enhanced MRI. They were evaluated as having almost no cortical bone rim but a periosteum like soft tissue envelope. Intraoperatively, following an extended curettage, this tissue was observed as an alive periosteal layer. Phenolisation was added and cavities were filled with allograft bone chips. The periosteum was sutured around the grafts. Additional stabilisation was performed by external fixator in 3 patients, dynamic compression hip screw in 1. Patients were followed up for a mean period of 47.8 months (9–84). Lesions healed after a mean period of 28.2 weeks (6–126). There was recurrence in 5 patients. The number of additional procedures necessary for relapsed lesions was 3 for one patient, 2 for another patient and 1 for the remaining 2 patients. Time to healing was not included for 1 patient who refused surgery for relapse and another patient who recently underwent surgery for relapse. One patient healed with a deformity. Aneurysmal bone cysts may present as highly aggressive local bone lesions. Even in such a subgroup, resection to prevent relapses seems an exaggerated procedure. Extended curretage and packing may yield satisfactory results, with acceptable recurrence rates

Abstract. Background. Schwannomas are slow-growing, benign tumours normally originating from the Schwann cells of the nerve sheath. Intraosseous schwannoma accounts for 0.175% of primary bone tumours and extremely rare especially outside the axial skeleton. Monoclonal gammopathy has been associated with soft tissue schwannomas but never with the intraosseous variety. Presenting problem. A 55-year-old woman with a background of monoclonal gammopathy of undetermined significance (MGUS) presented with a 2-year history of right thigh pain. CT scan showed a well defined, lytic lesion with a thin peripheral rim of sclerosis in the midshaft of the femur. MRI displayed a hyperintense, well marginated and homogenous lesion. Definitive diagnosis was made based on the classical histopathological appearance of schwannoma. Clinical management. We managed our patient with local curettage and prophylactic cephalomedullary nailing on the basis of a high mirel score. Discussion. Intraosseous schwannomas are poorly understood but most commonly reported in middle-aged women. Radiologically, their differential diagnosis includes malignant bone tumours, solitary bone cysts, aneurysmal bone cysts and giant cell tumours. As a result, they are usually diagnosed incidentally on histology. Although malignant transformation is possible in soft tissue schwannomas, all intraosseous schwannomas reported to date have been benign. This case demonstrates the importance of suspecting intraosseous schwannoma as a differential diagnosis for lytic bone lesions to avoid the overtreatment of patients. We also highlight monoclonal gammopathy of undetermined significance as a potential risk factor for a poorly understood disease and make recommendations about the appropriate management of these lesions. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction:. Sinus histiocytosis with massive lymphadenopathy (SHML) also known as Rosai – Dorfman disease is a disease of bone marrow stem cell origin. It affects lymph nodes primarily. Solitary bone lesions are very rare and can cause diagnostic difficulty. Aim:. To increase the awareness of SHML as a cause of cystic bone lesions. Materials and methods:. A 2 year old presented with 4 months history of pain and swelling of the distal forearm. There was no history of tuberculosis or HIV disease. The swelling was 4 × 3 cm firm, non-fluctuant and slightly tender. There were no lymph nodes. Radiographs showed an oval cystic lesion expanding with a well-defined margin. The ulnar cortex was deficient. CT scan confirmed a cystic lesion with contents of granulation tissue. The Hb and WCC were normal, ESR 20 was, CRP<5 and mantoux was negative. At surgery the lesion was curretted. The contents resembled tuberculous granulation but there was no caseation. The borders were well formed, the ulnar cortex was deficient. Results:. The histology revealed granulation tissue with numerous large histiocytes and immuno chemistry confirmed Rosai Dorfman disease. Healing with sclerosis was seen at 6 months. Discussion:. Rosai Dorfman disease is a systemic disease of bone marrow stem cells and lymphadenopathy is the prominent manifestation. Only ±8% of cases have been reported with bone involvement and 4% of these had no lymphadenopathy. The lesions are cystic and medullary but cortical involvement can occur. Solitary ossseous lesions characterized by a background of histocytes without eosinophils can mimic Langerhans histocytosis, localized osteomyelitis, fibrous dysplasia, tuberculosis, simple or aneurysmal bone cysts and metastatic deposits. Conclusion:. Lesions of haematopoetic origin should be considered in the diagnosis of lucent bone lesions in children