Metaphyseal and diaphyseal chondroblastomas

Periosteal chondroblastoma of the femoral neck: two cases and a review of the literature

Chondroblastoma is a rare benign cartilaginous tumor mostly confined to the epiphyses and apophyses. Cases outside the epiphyseal region are exceedingly rare. Extramedullary chondroblastomas are exceptional; to our knowledge, only two cases qualified as "periosteal chondroblastoma" have been described in the literature. We report two cases of metaphyseal periosteal chondroblastoma both located on the inferior surface of the femoral neck. Both cases were paucicellular with an unusual dense sclerotic reaction. The diagnosis of chondroblastoma was supported by the expression of histone 3.3, K36M mutant in tumor cells.

Distal Femoral Non-Epiphyseal Cortical Chondroblastoma Confirmed with H3F3B p. Lys36Met Mutation

Background: Chondroblastoma is a primary bone tumor typically arising from the intramedullary space of the epiphysis or epimetaphysis. A non-epiphyseal chondroblastoma is uncommon. Case report: An 11-year-old girl presented with an eccentric cortical osteolytic lesion in the distal femur metaphysis. The typical morphology, diffuse H3.3 K36M immunohistochemical expression and H3F3B point mutation (c. 110A > T) unequivocally supported the diagnosis of chondroblastoma. Discussion: We described a non-epiphyseal cortical-based chondroblastoma involving the distal femur harboring the typical H3F3B mutation. Non-epiphyseal chondroblastoma may harbor the H3F3B mutation.

Metaphyseal chondroblastoma in a pediatric patient

Chondroblastoma is a rare, benign neoplasm usually located in the epiphyses and apophyses of the long bones in the immature skeleton. Radiologically, these tumors have a classic appearance of a lytic lesion with chondroid matrix surrounded by a thin sclerotic rim. Here, we describe the case of a 5-year-old male who presented with a chondroblastoma unusually located exclusively in the metaphyseal region, which led to an elusive diagnosis. The presence of tumors outlying the traditional location or epidemiological spectrum, along with the potential for histopathological misdiagnosis, can pose a diagnostic and therapeutic challenge for the treating team.

Benign Bone Lesions Found in Childhood

Benign bone tumors are a wide variety of usually asymptomatic neoplasms, which in most cases are diagnosed due to secondary causes. As such, their real incidence is unknown. In the majority of cases, plain radiographs are enough for diagnosis; more advanced imaging, such as CT scan or MRI is sometimes performed for equivocal lesions. Treatment approach depends on whether the lesion is symptomatic and the risk of further progression, or development of secondary malignancies. When non expectant management is decided, treatment options include minimally invasive methods and surgery.

A report of an intracortical chondroblastoma of the diaphysis in a skeletally mature patient

Chondroblastomas characteristically occur in skeletally immature patients, and arise within the medullary canal of the epiphysis. We report a rare case of an intracortical chondroblastoma arising in the diaphysis, and occurring in an adult in his 3^rd decade of life. Immunohistochemistry results were critical to confirmation of this rare diagnosis, with immunohistochemistry showing S100, DOG1, and H3K36me3 positivity in the neoplastic cells.

Radio Frequency Ablation for the Treatment of Appendicular Skeleton Chondroblastoma: Is It an Excellent Alternative? Systematic Review and Meta-Analysis

Radio frequency ablation (RFA) is a minimally invasive technique that has become recognized in clinical practice for treating chondroblastoma, although curettage with bone graft is the standard treatment. Chondroblastoma is a locally aggressive cartilaginous bone tumor, representing nearly 5% of benign bone tumors. Chondroblastoma shows a preference toward the epiphysis or apophysis of long bones, but it was also reported in vertebrae and flat bones. The management of chondroblastoma could be challenging due to the risk to injure the epiphyseal plate or difficult location. The aim of this study was to determine if RFA is a suitable alternative to curettage with bone graft for the treatment of chondroblastoma. Moreover, there will be an evaluation of RFA's effectiveness in terms of symptoms relief; we also define the proper size of the lesion to be treated with RFA, and discuss the complications after the procedure, including the recurrence rate. Furthermore, we review the best imaging method to evaluate the therapeutic response of RFA and for the detection of residual disease early after the ablation. A comprehensive PubMed and Google Scholar search followed the Preferred Reporting Items for Systematic Review and Meta-Analysis 2020 checklist guidelines. Ninety-seven patients were identified after reviewing the available full texts of nine articles. The results of the current review provide further evidence to support the use of RFA as an alternative option to surgery.

Chondroblastoma of the knee in a teenager

Chondroblastoma is an uncommon osseous neoplasm that accounts for less than 1% of all bone tumors. Characteristically it arises in the epiphysis or apophysis of long bones in young patients and may extend into the metaphysis. A sixteen-year-old male presents with a 1-year history of left knee pain associated with joint stiffness and interfering with performing daily activities. Radiographic and contrast enhanced magnetic resonance imaging favored the diagnosis of chondroblastoma. This was then confirmed histologically. The clinical signs and symptoms of Chondroblastoma are usually nonspecific, pain is most often moderate and can be revealed as a result of a trauma. The definitive diagnosis is mainly pathological due to the lack of specificity of radiological findings consistent with the presented case.

Chondroid Tumors of Bone

Recent scholarship on enchondroma, chondrosarcoma, and chondroblastoma is presented. The focus of this article is on the imaging appearance of these tumors and the means by which they can be distinguished from one another by both clinical and imaging criteria.

Total Calcanectomy and Bilateral Iliac Bone Autograft Reconstruction for the Treatment of Calcaneal Chondroblastoma Involving a Secondary Aneurysmal Bone Cyst: A Case Report and Literature Review

Chondroblastoma is a rare, benign, cartilaginous-derived tumor accounting for ∼1% to 2% of all primary bone tumors and almost 9% of all benign bone tumors. In this case report, we describe a patient with chondroblastoma and a secondary aneurysmal bone cyst, with the adjacent talus being mildly affected. The initial diagnosis was giant cell tumor and was then confirmed after computed tomography-assisted biopsy. We performed a total calcanectomy via bilateral structural iliac bone autografting to relieve pain and reconstruct the loadbearing function because of the presence of extensive lesions. The patient was pain free and expressed satisfaction with postsurgical dorsiflexion and plantarflexion function at the 60-month follow-up visit. Radiographic images showed that the autografted iliac bone was completely healed, with no evidence of local recurrence.

Eight-Year Follow-Up Using a Fresh Osteochondral Allograft for a Femoral Head Chondroblastoma in a 17-Year-Old Patient

Chondroblastoma is a rare benign tumor that affects the epiphysis of long bones in adolescents. Chondroblastoma located in the femoral head is associated with a higher recurrence rate and carries the additional risks of head collapse and degenerative hip disease. Aggressive curettage followed by bone grafting is the current mainstay of treatment. To our knowledge, the long-term postoperative outcome of this technique remains unknown due to the short follow-up of previous case reports. We present the case of a 17-year-old male who underwent fresh osteochondral allograft following curettage of a femoral head chondroblastoma, using a Ganz surgical hip dislocation. He made an uneventful recovery without tumor recurrence. The patient was followed up to 8 years postoperatively. However, there were clinical and radiographic degenerative changes at 6 years of follow-up.

Functional and Oncological Outcome After Treatment of Chondroblastoma With Intralesional Curettage

BACKGROUND

Chondroblastoma is a rare cartilaginous benign bone tumor that commonly arises in long bones of young people. Surgical management is the primary treatment of choice for chondroblastoma and it entails adequate intralesional curettage alone or in combination with adjuvants. This study was performed to describe the epidemiological characteristics and clinical and radiologic results of intralesional curettage of chondroblastoma.

METHODS

This was a retrospective study which included an analysis of 91 patients with chondroblastoma who were treated with intralesional curettage and were followed up between 1994 and 2014 for at least 3 years. Epidemiological data, clinical symptoms, radiologic and histologic investigations, surgery, functional outcomes, complications, and local recurrence rate were analyzed.

RESULTS

There were 60 males (65.9%) and 31 females (34.1%) with a mean age of 16.4 years. The most commonly involved bone was the proximal tibia in 24 patients (26.4%), followed by distal femur in 20 patients (22%), proximal humerus in 17 patients (18.7%) and proximal femur in 15 patients (16.6%). All patients underwent intralesional curettage. High-speed burr was used in 66 patients (72.5%). The resultant cavity was filled with autogenous bone graft, bone substitute, bone cement or a combination of bone graft and cement. Four patients (4.4%) had complications. Three patients (3.3%) developed local recurrence. Age, site, history of previous intervention or pathologic fracture had no impact on the rate of recurrence. The mean Musculoskeletal Tumor Society (MSTS) score was 28.88 (range, 24 to 30) points.

CONCLUSIONS

Thorough curettage using high-speed burr and bone-grafting or bone cement in the treatment of chondroblastoma has good local control, low recurrence rate and excellent functional long-term outcome.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

[Benign tumours and tumour-like lesions of the bone : General treatment principles]

BACKGROUND

Benign bone lesions are much more common than malignant lesions. Some benign bone tumors have a characteristic and typical radiographic appearance, while others are more challenging. Therapy of benign bone tumors differs greatly. While the majority of benign bone tumors do not require surgical therapy, other specific lesions, e. g. aneurysmal bone cysts or giant cell tumors (GCT) of the bone require surgery due to their locally aggressive behavior.

DIAGNOSTICS

The major challenge for the radiologist and/or pathologist is the differentiation between a benign and low-grade malignant lesion (e. g. enchondroma versus low-grade chondrosarcoma) for which all available clinical and radiographic information is mandatory. Therefore, surgical therapy is rather more often performed than necessary due to uncertainty in many cases.

THERAPY

Novel systemic therapies are available for fibrous dysplasia and GCT of the bone: Fibrous dysplasia can be treated with bisphosphonates, and GCT responds to denosumab. In fact, denosumab has been approved for the treatment of irresectable GCT. Osteoid osteoma is fairly easy to recognize and also to treat given the characteristic clinical presentation and rapid and effective response to local therapy (possible as percutaneous thermo-/laser ablation). In summary, several therapeutic options exist for benign bone tumors, and the choice depends upon the tendency/risk of local recurrence, the rate of surgical complications, options for defect reconstruction, postoperative functional deficits, and specific patient characteristics.

Chondroblastoma of the distal femoral metaphysis: A case report with emphasis on imaging findings and differential diagnosis

Chondroblastoma is a rare benign tumor, consisting of tissue resembling foetal cartilage, and arising in the epiphyses, or apophyses of long tubular bone. However, chondroblastoma of the cortex of the long bone metaphysis is extremely rare.A 15-year-old girl presented a 10-month history of intermittent knee pain and without mobility limitation. X ray, computed tomography (CT), and magnetic resonance imaging (MRI) showed a slightly expansile lytic lesion involving the metaphyseal cortex of the left distal femur. During histological examination, typical features of chondroblastoma were observed. Chondroblastoma was definitely and histologically diagnosed. Surgical procedures included intralesional tumor curettage and allograft bone implantation. The patient was discharged without any complications 1 week after surgery and there was no recurrence during a 10-month follow-up.This report describes a case of chondroblastoma in the metaphyseal cortex of the distal femur and serves as a reminder of the atypical anatomic location of chondroblastoma. Patients in an appropriate age group with typical imaging features may be diagnosed with chondroblastoma despite its rare location.

Diagnosing and discriminating between primary and secondary aneurysmal bone cysts

Aneurysmal bone cysts (ABCs) are benign bony lesions frequently accompanied by multiple cystic lesions and aggressive bone destruction. They are relatively rare lesions, representing only 1% of bone tumors. The pathogenesis of ABCs has yet to be elucidated. In the present study, a series of 22 cases of primary and secondary ABC from patients treated in Department of Orthopedic Surgery, Kagoshima University Hospital (Kagoshima, Japan) from 2001–2015 were retrospectively analyzed. The average age at the time of diagnosis of primary ABC was 17.9 years. Intralesional curettage and artificial bone grafting were performed in the majority of the patients with primary ABC. The local recurrence rate following curettage for primary ABC was 18%, and the cause of local recurrence was considered to be insufficient curettage. Although no adjuvant therapy was administered during the surgeries, it may assist the prevention of local recurrence in certain cases. The cases of secondary ABC were preceded by benign bone tumors, including fibrous dysplasia, giant cell tumors, chondroblastoma and non-ossifying fibroma. The features of the secondary ABC typically reflected those of the preceding bone tumor. In the majority of cases, distinguishing the primary ABC from the secondary ABC was possible based on characteristic features, including age of the patient at diagnosis and the tumor location. In cases that exhibit ambiguous features, including a soft tissue mass or a thick septal enhancement on the preoperative magnetic resonance images, a biopsy must be obtained in order to exclude other types of aggressive bone tumors, including giant cell tumor, osteosarcoma and telangiectatic osteosarcoma.

Surface-based chondroblastoma of the tibia: a unique presentation

BACKGROUND

Chondroblastoma is a benign tumor classically located within the epiphysis of the long bones. The tumor is believed to arise from immature cells of the epiphyseal plate. Purely metaphyseal or diaphyseal chondroblastoma is exceedingly uncommon, occurring in approximately 2% of chondroblastoma cases. In all of these non-epiphyseal-based cases, the tumor has been intramedullary.

METHODS

We describe the histologic and imaging features of the first detailed description of a surface-based chondroblastoma.

RESULTS

The tumor was located in the anteromedial midshaft of the tibia in a 47-year-old male.

CONCLUSION

We discuss the diagnostic considerations and possible etiology of chondroblastoma given this unusual location.

Chondroblastoma of bone in the extremities: a multicenter retrospective study

BACKGROUND

Chondroblastoma is a rare benign cartilage tumor that commonly occurs in children and adolescents. This study was designed to review the epidemiologic characteristics and outcomes of surgical management in a large series of patients with extremity chondroblastoma.

METHODS

We performed a multicenter retrospective analysis of 199 patients with extremity chondroblastoma. Clinical data, radiographic images, histological findings, treatment, and outcome were analyzed.

RESULTS

There were 145 male patients and fifty-four female patients with a mean age of 18.0 years. The most commonly involved bone was the proximal part of the tibia (fifty-five patients [27.6%]), followed by the proximal part of the femur (fifty-two patients [26.1%]) and the distal part of the femur (thirty-eight patients [19.1%]). Prior to presentation, 73.4% (146 of 199 patients) experienced pain. The mean duration of pain and other symptoms was 8.7 months. The physis was open in 25.7%, it was closing in 22.2%, and it was closed in 52.1% of the patients at the time of presentation. One hundred and twenty-six patients had at least twenty-four months of follow-up; their mean follow-up duration was 62.1 months (range, twenty-four to 190 months). Initial treatment was curettage for 119 patients (94.4%) and en bloc resection for seven patients (5.6%). The local recurrence rate was 5.0% after curettage and 0% after resection. The only significant factor related to recurrence was the location of the lesion in the proximal part of the humerus (p = 0.001).

CONCLUSIONS

Chondroblastoma occurs most frequently in the proximal part of the tibia and the proximal part of the femur with significant male predilection. In this series, recurrence was most frequent in the proximal part of the humerus. Our results suggest that curettage and bone-grafting provide favorable local control and satisfactory functional outcome for patients with this disease.

LEVEL OF EVIDENCE

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

Reconstruction by bone transport after resection of benign tumors of tibia: A retrospective study of 38 patients

BACKGROUND

The commonly used reconstructive options after post resection defects in bone tumors like megaprosthesis, autograft, allograft, bone graft substitutes and recycled bone have their own demerits on a long term. Bone transport that regenerates patient's own bone is a less explored option of reconstruction after resection of benign bone tumors and reports on this are limited. This technique is very much relevant in tibia where Ilizarov fixator is surgeon and patient friendly. We report our experience.

MATERIALS AND METHODS

This is a retrospective series of resection and bone transport in 38 patients with benign tumor of tibia. There were 14 males and 24 females with mean age of 23.40 years (range 9-40 years). Lesion was located in proximal third tibia in 27, middle third in two and distal third in nine patients. The diagnosis was giant cell tumor in 32, chondroblastoma in three, chondromyxoid fibroma, enchondroma and desmoplasic fibroma in one patient each. The resection was intercalary in 28 and transarticular in 10 patients. Osteosynthesis was monofocal in three, bifocal in 31 and polyfocal in four cases.

RESULTS

Mean followup was 7.22 years (range 1.5-15 years). Mean resection length was 10.21 cm (range 3-22 cm). The mean duration of external fixator was 308.03 days (range 89-677 days) and mean external fixator index was 36.14 days/cm (range 16.84-97.43 days/cm). Twelve patients had difficulties in the form of 11 problems and five obstacles that were successfully managed. None of the patients had local recurrence of tumor or any long term complication. Mean Musculo-skeletal Tumour Society score at final followup was 27.18 (90.60%).

CONCLUSIONS

Bone transport is an excellent option after resection of benign tumors of tibia with good local control and functional outcome, despite minor difficulties that need timely management.

Chondroblastoma of the knee treated with resection and osteochondral allograft reconstruction

Case. This case report describes the operative management of 16-year-old male with a symptomatic chondroblastoma of the distal femur with breach of the chondral surface. Following appropriate imaging and core needle biopsy, the diagnosis was confirmed histologically. The patient then underwent intralesional curettage and osteochondral allograft reconstruction of the defect. At one-year follow-up the patient was pain-free and has obtained excellent range of motion. There is radiographic evidence of allograft incorporation and no evidence of local recurrence. Conclusion. Osteochondral allograft reconstruction is an effective option following marginal resection and curettage of chondroblastoma involving the chondral surface of the distal femur.

Pitfalls in the diagnosis of common benign bone tumours in children

Benign bone tumours in children are frequent lesions, often with a typical and very identifiable radiological presentation. However, their natural evolution and complications may be the source of variations and errors in interpretation. It is therefore important to understand the possible sources of change in the radiological aspect and to be familiar with common pseudotumoral lesions. The main aim of this review is to review typical aspects of the most common benign bone tumours in children, as well as less frequent variants of these tumours.

Teaching points

• Benign bone tumours in children may have atypical radiological presentations.

• Some normal variants are commonly misinterpreted as tumours.

• X-ray is the main imaging tool for focal bone lesions.

• Depending on the X-ray, complementary imaging examinations and biopsy may be necessary.

A fatal case of pure metaphyseal chondroblastoma

The chondroblastoma (CB) is a rare cartilaginous tumour; it represents less than 1% of all bone tumours. It is mostly localised at the level of the epiphysis of long bones. We report a fatal case of pure metaphyseal CB of the tibia in a 9-year-old boy whose pulmonary metastases developed soon after operative therapy of the primary tumour.

Inhibition of mTOR and HIF pathways diminishes chondro-osteogenesis and cell proliferation in chondroblastoma

Chondroblastoma (CBL) is a benign bone tumor occurring mostly in teenagers. Despite this, CBL can recur and metastasize after curettage, which may impede normal epiphysis. In search of a novel targeted therapy for CBL, we aimed at BMP-2, a factor critical for chondro-osteogenesis and chondrocyte proliferation. Two pathways upstream of BMP-2, the mTOR and HIF, were targeted with rapamycin (Rapa) and FM19G11 (FM), respectively. Using immunohistochemistry, we found BMP-2 was highly expressed in CBL tissues. CBL cells explanted and confirmed with higher BMP-2 level than normal cartilage. Protumorigenic effect of Rapa and FM on CBL cells were transduced via BMP-2. Combination of Rapa and FM conferred stronger inhibition of cell proliferation than either monotherapy and inhibited levels of chondro-osteogenic markers (Sox9, aggrecan, and type II collagen). To minimize the adverse effect of Rapa, we performed screening in essential amino acids and found leucine deprivation-sensitized CBL cells to Rapa. Combination treatment of low dose Rapa, FM, and leucine deprivation conferred compatible inhibitory effects on CBL cell proliferation, chondro-osteogenic potential, and tumorigenic capacity. We conclude that targeting BMP-2 using mTOR/HIF inhibition could potently curb the disease. Addition of low-leucine diet could lower the dose of rapamycin in chase for less toxicity.

Primary aggressive chondroblastoma of the humerus: an unusual imaging presentation

Chondroblastoma is an uncommon primary benign cartilage-producing neoplasm representing only 1% of all primary bone neoplasia, with male preponderance. It has a predilection to present in any bone ossified in the endochondral pattern. Epiphyseal location, small size, geographic margins, and cartilaginous matrix are virtually pathognomonic radiologic features of this tumor. The tumor rarely transgresses the parent bone to invade adjacent structures. We describe a histologically proven case of chondroblastoma, invading the adjacent glenohumeral joint in a 15-year-old female presented with shoulder pain, in which radiological features belied the nature of the tumor.

Chondroblastoma and chondromyxoid fibroma

Chondroblastoma and chondromyxoid fibroma are benign but locally aggressive bone tumors. Chondroblastoma, a destructive lesion with a thin radiodense border, is usually seen in the epiphysis of long bones. Chondromyxoid fibroma presents as a bigger, lucent, loculated lesion with a sharp sclerotic margin in the metaphysis of long bones. Although uncommon, these tumors can be challenging to manage. They share similarities in pathology that could be related to their histogenic similarity. Very rarely, chondroblastoma may lead to lung metastases; however, the mechanism is not well understood.

The imaging of cartilaginous bone tumours. I. Benign lesions

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.