Benign Primary Bone Tumor Research Articles

Giant Cell Tumor of Distal Ulna – A Rare Case Report

Among the benign primary bone tumors, Giant cell tumor (GCT) accounts for about 3% to -5%. It is a locally aggressive tumor with maximum incidence between 20 to and 40 years of age. The sites where GCT is most commonly seen are distal femur, and proximal tibia followed by distal end radius. Distal end of ulna is a rare site with an incidence of only 0.45% to -3.2%. We report a case of a 32- year- old male with (GCT) giant cell tumor of the left distal ulna. We managed the patient with en bloc resection of distal ulna along with reconstruction of distal radio ulnar joint (DRUJ) and triangular fibro cartilage complex (TFCC) using proximal fibula graft and palmaris longus graft. DRUJ was stabiliszed with a k- wire. After 1 year of follow- up, patient showed good results in terms of range of movements of the wrist joint with no evidence of recurrence.

Giant Cell Tumor of the Proximal Phalanx of the Little Finger about One Case in Our Milieu

Giant cell tumor is a benign primary bone tumor. The phalangeal localization is rare. It is distinguished from other locations by the local aggressiveness of the tumor and a high rate of recurrence. We report one case of a 25-year-old right-handed nurse with no reported pathological history who complained about an ulcero-budding mass of the right little finger evolving one year ago. She would have initially consulted a bonesetter who would have taken care of her by using decoctions. The hand X-ray showed an osteolytic tumor of the first phalanx of the right little finger with a “honeycomb” appearance invading the soft tissues. We carried out the amputation of the radius. The postoperative course was simple with healing of the surgical wound and disappearance of the axillary adenopathy. The surgical specimen after anatomopathology exam concluded to be a grade 2 giant cell tumor of Senerkin.

Epidemiology of primary bone tumours in Nigeria: a systematic review

BACKGROUND: Primary bone tumours, although rare, are an important rising cause of morbidity and mortality in Africa. Late presentation, delayed diagnosis and failure to obtain consent for surgical procedures are important causes of loss of limb and life especially in the West African subregion. Existing data on primary bone tumours in Nigeria have been based on studies performed at various regional levels. The aim of this study is to determine the epidemiological pattern of primary bone tumours in Nigeria in general, including demographics, predominant tumour types and predominant skeletal location by reviewing existing data METHODS: A search of the following databases: University of Edinburgh Library, PubMed, CINAHL and SCOPUS from 2000 till January 2021 following PRISMA guidelines was conducted to identify studies conducted in Nigeria with relevant epidemiological data on primary bone tumours in Nigeria RESULTS: The search yielded a total of 952 hits from which seven hospital-based retrospective studies met the inclusion criteria for review. The estimated incidence rate of primary bone tumours ranged from 0.08 to 0.31 per 100 000 population. All studies showed a male preponderance. The peak age group of individuals presenting with both benign and malignant primary bone tumours was 11-20 years. Overall, benign tumours were more common. Osteochondromas were the most common benign tumours, while the commonest malignant tumours identified were osteosarcomas. The most common location for both benign and malignant tumours were the tibia and fibula CONCLUSION: Nigeria shares some similar epidemiological characteristics of primary bone tumour with other countries; however, some peculiar differences have been identified in this study. Population-based studies are required to obtain more accurate epidemiological data about this disease Level of evidence: Level 2

The Effect of Denosumab and Risk Factors for Recurrence in Spinal Giant Cell Tumors: A Systematic Review and Meta-Analysis.

PurposeGiant cell tumors (GCTs) are common benign primary bone tumors and are well known for their locally aggressive performance and tendency to recur. The purpose of this study was to analyze the effects of denosumab and risk factors for recurrent spinal GCTs.Materials and MethodsWe searched PubMed, EMBASE, Web of Science, and Cochrane Library databases to identify differences between individuals treated with and without denosumab and risk factors for spinal GCT recurrence. Patient data, including age, sex, tumor resection range, location, denosumab use, Campanacci grade, and radiotherapy, were documented. Comparable factors were evaluated using odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs).ResultsSixteen studies were included. The overall incidence of spinal GCT recurrence was 29%. Campanacci grade III tumors showed better recurrence outcomes than grades I and II (OR, 16.36; 95% CI, 4.19–63.93; p<0.001). Gross total resection (OR, 0.09; 95% CI, 0.04–0.19; p<0.001), radiotherapy (OR, 0.27; 95% CI, 0.11–0.65; p=0.004), and the use of denosumab during subtotal resection (OR, 2.95; 95% CI, 1.07–8.17; p=0.04) were important factors for reducing recurrence.ConclusionClinicians must consider the effects of gross total resection, radiotherapy use, and denosumab use in cases of subtotal resection during spinal GCT treatment. So far, many researchers have used denosumab in spinal GCT, but none have clearly suggested an endpoint. Most studies, however, recommend using it for more than 6 months.

Diagnostic features of lumbar canal osteochondroma and review of literature

Osteochondroma is a common benign primary bone tumor that can be multiple or solitary and is usually caused by a developmental defect in the growth plate. Osteochondroma usually arises from an osteochondroma near the ends of long bones and is less likely to occur in the spine. Data show that the incidence of single spinal osteochondroma is only 1.3%-4%, and the most common sites are cervical vertebra, thoracic vertebra, thoracolumbar and lumbar vertebra. Osteochondroma of the lumbar spine is rare because its ossification center generally ossified around 30 years of age, later than cervical and thoracic vertebrae. Only about 30% of patients with osteochondroma of the lumbar spine had intact cartilage caps. If the thickness of the cartilage cap is assessed, it is difficult to see on conventional radiographs. Conventional radiographic assessment is usually used to diagnose osteochondroma in the extremities, whereas radiographic diagnosis of osteochondroma in the spine is more difficult. This case was reported as a female patient with a single osteochondroma, which occurred in the lumbar spine and had a complete cartilage cap during the operation. This case is rare, which can provide some help for clinical practice to avoid misdiagnosis and missed treatment of this kind of disease.

Management of distal ulna giant cell tumor by en bloc resection and reconstructed by a novel technique

Giant cell tumor (GCT) is a locally aggressive benign primary bone tumor accounting for 20% of all the benign primary bone tumors. Peak incidence is between 20 and 45 years with slight female predominance. Distal end of ulna is a rare site for any primary bone tumor, especially 2-4 for giant cell tumors with reported incidence of 0.45 to 3.2% in literature. Considering local aggressive nature and high recurrence, resection is the treatment recommended. In such cases, instability of the ulnar stump and ulnar translation of the carpals are known 3-6 complications causing reduced grip strength. Literature review states, reconstruction with iliac bone graft and stabilization of the ulnar stump with tenodesis using extensor carpi ulnaris. We report a 34 year old female with giant cell tumor of the distal ulna treated by en bloc resection and reconstruction of the distal radio-ulnar joint (DRUJ) and triangular fibrocartilage (TFCC) complex with proximal fibula, palmaris longus graft with augmentation by extensor carpi ulnaris tenodesis and stabilization of the proximal stump with dynamic compression plate. This newer technique of DRUJ and TFCC reconstruction with proximal fibula and palmaris longus graft following en bloc resection of the distal ulna had excellent functional results with no evidence of recurrence after seven months follow-up. This case is presented for its rarity and novelty of the technique used for the anatomical reconstruction.

Implant cement spacer-a cost-effective solution for reconstruction of proximal humerus defects after tumor resection

The proximal humerus is a common location for both primary benign and malignant bone tumors and may require sacrificing deltoid muscles, axillary nerve and/or rotator cuff along with proximal humerus resection. Thus, post operatively shoulder movements are restricted. The main goals of reconstruction are to maintain a stable shoulder so that the function of elbow and hand can be optimized. Various reconstruction options are available after proximal humerus resection. We present our experience in using implant-cement spacers as a primary reconstruction option for limb salvage in the primary tumors of proximal humerus. All cases were retrieved from our prospectively maintained surgical database. 142 patients (96 males and 46 females) with a median age of 17.5 years (3–70 years) were operated with implant cement spacer between January 2006 and April 2019. Median follow up was 34 months (1–174 months). Functional outcome of the surgery was assessed in survivors by Musculoskeletal Tumor Society score (MSTS). Implant survival was assessed by Kaplan Meier analysis and competing risk analysis. On last follow up, out of 142 cases, 81 patients had died, 54 are alive and seven were lost to follow up. 18(13%) patients underwent revision surgery for symptomatic proximal migration, implant failure or infection. Four (2.8%) patients underwent forequarter amputation for local recurrence. The five years implant survival (IS) by Kaplan Meier analysis was 79.6% and as per competing risk analysis, the chances of implant revision are 12% and 18% at five and ten years respectively. Mean MSTS score in survivors was 71% (60–80%). Implant cement spacer is a cost-effective alternative for reconstruction of proximal humerus with revision rates and function comparable to other reconstructions in cases where deltoid, axillary nerve and/or rotator cuff are excised.

Imaging Spectrum of Calvarial Abnormalities.

Calvarial abnormalities are usually discovered incidentally on radiologic studies or less commonly manifest with symptoms. This narrative review describes the imaging spectrum of the abnormal calvaria. The extent, multiplicity, and other imaging features of calvarial abnormalities can be combined with the clinical information to establish a final diagnosis or at least narrow the differential considerations. Prior trauma (congenital depression, leptomeningeal cysts, posttraumatic osteolysis), surgical intervention (flap osteonecrosis and burr holes), infection, and inflammatory processes (sarcoidosis) can result in focal bone loss, which may also be seen with idiopathic disorders without (bilateral parietal thinning and Gorham disease) or with (Parry-Romberg syndrome) atrophy of the overlying soft tissues. Anatomic variants (arachnoid granulations, venous lakes, parietal foramina) and certain congenital lesions (epidermoid and dermoid cysts, atretic encephalocele, sinus pericranii, and aplasia cutis congenita) manifest as solitary lytic lesions. Other congenital entities (lacunar skull and dysplasia) display a diffuse pattern of skull involvement. Several benign and malignant primary bone tumors involve the calvaria and manifest as lytic, sclerotic, mixed lytic and sclerotic, or thinning lesions, whereas multifocal disease is mainly due to hematologic or secondary malignancies. Metabolic disorders such as rickets, hyperparathyroidism, renal osteodystrophy, acromegaly, and Paget disease involve the calvaria in a more diffuse pattern. Online supplemental material is available for this article. ©RSNA, 2021.

Evaluation of local and circulating osteopontin in malignant and benign primary bone tumors

PurposeThe development of novel and efficient biomarkers for primary bone cancers is of grave importance. MethodsThe expression pattern of osteopontin (OPN) was investigated in the 153 patients with benign (n = 72) and malignant (n = 81) primary bone cancers. Both local and circulating OPN mRNA expression levels and their protein concentration in serum and tumor site were assessed using real-time qRT-PCR, ELISA, and immunohistochemistry techniques, respectively. As a control, 29 healthy individuals were considered. The number of 153 tumor tissue specimens and the 153 paired margins were taken on surgical resection from the patients. 153 blood samples were also drained from all participants, then peripheral blood mononuclear cells (PBMC) and sera were separated. ResultsThe mean mRNA expression was significantly higher in all of the cancerous tissues than the paired margins and the PBMC of the patients than the controls. Consistently, the protein concentrations of OPN in serum and tumor tissues were significantly higher in the patients. Furthermore, the malignant cases had significantly elevated the mRNA levels and the protein compared to the benign cases. OPN could potentially differentiate the patients from the controls with 100% sensitivity and specificity in serum. Moreover, OPN could predict some of the malignant cases' clinicopathological features, including metastasis, recurrence, grade, and response to chemotherapy. ConclusionsIn conclusion, OPN might be involved in the pathogenesis of primary bone tumors and can be considered as a potential biomarker to bone cancer diagnosis.

Clinical and Radiographic Outcomes Following Management of Benign Bone Lesions of the Hand With Calcium Phosphate Bone Cement

Background: Enchondromas are benign primary bone tumors that often occur in the hand. Surgical curettage is often indicated for symptomatic lesions, but controversy exists regarding whether and how best to fill the void. Autograft and allograft bone in addition to various types of plaster or cement are common means addressing the postexcision defect. This study reports long-term clinical and radiographic outcomes of excision with calcium phosphate bone cement (CPC) for benign bone lesions of the hand. Methods: This is a retrospective review of symptomatic benign bone lesions treated with curettage and CPC by a single surgeon with long-term follow-up. Following Institutional Review Board approval, consenting patients returned for postoperative research visits, during which radiographs were taken and functional outcome scores were measured. Results: Of the 7 patients who consented to participate, all initially presented with pain at the site of the tumor. Average follow-up time was over 6 years and overall functional outcome scores were good with early return to work. Cementation filled nearly the entire lesion on postoperative films and there were no postoperative fractures, infections, wound problems, or revision surgeries. Conclusions: This study reports good long-term radiographic and functional outcomes, without recurrences, in a series of patients with symptomatic benign bone lesions of the hand when treated with excision and CPC by a single surgeon.

Periosteal Variety of Sacral Osteoid Osteoma Encroaching into the Spinal Canal – Treatment with a Tubular Retractor System: Case Report

Background: Osteoid osteomas are benign primary bone tumors with a predilection for posterior elements of the spinal column. Complete surgical excision through a traditional open approach is the treatment of choice for patients not responding to non-steroidal anti-inflammatory medications and patients with contraindications for nidus ablation. The study aims to highlight an alternative minimally invasive technique for complete surgical excision of osteoid osteoma encroaching into the spinal canal. Methods: We report a case of 22 years-old obese male suffering from left S1 radiculopathy and night pain. Magnetic resonance imaging and computed tomography (CT)-scan of the lumbosacral region revealed a benign bony lesion of size 13 mm × 11 mm × 8 mm encroaching from S1 lamina into the spinal canal and compressing left S1 root. Peri-lesional bony sclerosis and soft tissue edema were absent. In view of obesity and a small size of the lesion, it was decided to remove the lesion with a tubular retractor system under general anesthesia. Complete resection of the lesion was carried out sparing the L5-S1 facet, with a minimally invasive approach. Results: Patient had complete symptomatic improvement after the surgery. Histopathology showed interconnected trabeculae of woven bone matrix rimmed by osteoclasts consistent with the diagnosis of osteoid osteoma. Post-operative CT scan showed that the nidus was removed completely and important structures such as facet, pedicle, and midline posterior ligament complex were preserved. The patient resumed his daily activities and remained symptoms-free at the end of 6 months of follow-up. Conclusion: Minimally invasive surgery using a tubular retractor system can be safe and effective alternative to traditional open surgery for excision of osteoid osteoma from the posterior elements. Faster recovery, minimal tissue damage, and early return to work are added advantages for an obese patient undergoing minimally invasive total surgical excision. Keywords: Benign bone tumors, Sacral spine, Osteoid osteoma, Periosteal osteoid osteoma, Minimally invasive spine surgery, Tubular retractor system

Kliničko-patološke karakteristike tumora kostiju karlice

Introduction: Bone tumors are rare neoplasms whose therapy depends on the location. Pelvic bones represent a special anatomical entity diagnosis and therapy of pelvic tumors in addition to the pathohistological type largely depends on the anatomical specifics of that region. Aim: The aim of this study was to show the frequency, as well as clinical and pathological characteristics of primary and secondary tumors of the pelvic bones. Material and methods: The research as a descriptive study in the period from January 1, to December 31, 2019 at the Institute of Pathology of the Medical Faculty of the University of Belgrade and includes 33 patients. Demographic, clinical and radiological data were obtained from the Bone Tumor Registry. Statistical processing and analysis were done in the Statistical Package for Social Science SPSS Windows version 22 (IBM Chicago, Ilinois, USA). Results: Out of 33 patients, 55% had secondary pelvic tumors, primarily cancer metastases (37%). In 21% of cases, primary malignant bone tumor as diagnosed, and in 12%, primary benign bone tumor. Hematopoietic neoplasms were verified in 12%. Conclusion: Pelvic bone tumors are not common, but these neoplasms, in orthopedic oncology, represents their malignant biological behavior are of great importance. The most common primary malignant tumor in adults is chondrosarcoma, and in children Ewing sarcoma. Highest frequency for pelvic bone metastases has lung cancer. Plasmacytoma in adults, Langerhans cellular histiocytosis in children are hematological neoplasms seen at this site.

Imaging of Mixed and Radiopaque Jaw Lesions

Radiopaque lesions and lesions of mixed density are less frequent than radiolucent lesions of the jawbones. They comprise a spectrum of odontogenic and non-odontogenic lesions. The latter group includes inherited and developmental disorders, osteomyelitis, and benign and malignant primary bone tumors and metastases. Most odontogenic radiopaque or mixed lesions are either related to the apex or more rarely to the crown of the tooth, although there are exceptions to this rule. Some lesions, such as a torus mandibularis and torus palatinus, have a characteristic location, whereas others show no relationship to the dentition. This article describes the most characteristic and prevalent radiopaque and mixed lesions of the jaws and their imaging characteristics. Paget's disease, fibrous dysplasia, and rare sclerotic bone diseases of the maxillofacial bones are discussed elsewhere in this issue. Careful correlation of clinical presentation, panoramic radiographs, cone beam computed tomography, and histopathology are the cornerstones for appropriate lesion characterization.

Full endoscopic resection of a lumbar osteoblastoma: technical note.

Osteoblastomas are a rare, benign primary bone tumor accounting for 1% of all primary bone tumors, with 40% occurring within the spine. Gross-total resection (GTR) is curative, although depending on location, this can require destabilization of the spine and necessitate instrumented fixation. Through the use of minimally invasive, muscle-sparing approaches, these lesions can be resected while maintaining structural integrity of the spine. The authors present a case report and technical note of a single patient describing the use of a purely endoscopic technique to resect a right L5 superior articulating process osteoblastoma in a 45-year-old woman. The patient underwent an image-guided endoscopic resection of her superior articulating facet osteoblastoma. Intraoperative CT demonstrated GTR. On postoperative examination, she remained neurologically intact with resolution of her pain. At follow-up, she remained pain free. Resection of lumbar osteoblastoma through a fully endoscopic approach was a safe and effective technique in this patient. This technique allowed for GTR without compromising spinal structural integrity, thus eliminating the need for instrumented fixation.

Case of Cervicothoracic Spine Osteoblastoma in a 5 Year-old Boy

Osteobalstoma is a benign primary bone tumor which represents 3% of all benign tumors and 1% of all bone tumors. It is localized commonly in the spine. We report the case of a 5 year-old boy with cervicothoracic spine osteoblastoma. The incidence of osteoblastoma is between de second and third decade; our case was seen in the first decade. The evaluation by computed tomography scan and magnetic resonance imaging show the lesion of posterior elements of D1 vertebrae with extension to 4 upper and underlying vertebrae. The decision of excision was taken a long time of discussion because for surgical team, the lesion was mimicking malignancy of the spine. The child had an uneventful postoperative recovery and the pain resolved after surgery. The objective of this article was to report a case of extensive osteoblastoma and to alert the clinician to avoid delay management due to differential diagnosis. Keywords: Osteoblatoma; Pediatric population; MRI; Surgical treatment.

Management of benign bone tumors in a tertiary hospital in North West Nigeria

Background: Tumors originating from bone and cartilage are mostly benign with distinct feature of non-metastasis. Such tumors may occur in any bone of the skeleton, and are more frequent in the younger age group. Complete excision and curettage as the main modality of treatment is in most of the cases adequate with satisfactory outcomes. This study reviewed the histological types of primary benign bone tumors and results of various surgical options of treatment offered. Patients and Methods: Thirty-nine patients with histologically confirmed benign bone tumors arising from upper and lower limbs were retrospectively selected over 13-year period from August 2007 to August 2020 and analyzed. Results: Twenty-two patients were males while 17 were females. Age range is between 3 and 53 years, mean of 24.8 years with highest frequency in the third decade. Histological types were 18 giant cell tumors, 14 osteochondromas, 3 Ecchondromas, 2 Enchondromas and 2 Ossifying fibromas. Twenty five patients had excisional biopsy alone, 6 had excisional biopsy and bone grafting, 3 had limb amputation/dis articulation, 2 had excision with limb reconstruction using dynamic external devices, a patient underwent excision with bone cementing, one had excision and joint replacement (hip hemiarthroplasty), and another one had excision and joint arthrodesis. Conclusion: Benign bone tumors remain largely asymptomatic accounting for the late presentation. Excisional biopsy alone remains the commonest modality of treatment with good result. Giant cell tumor remained the commonest benign tumor in our center. Population based study is needed to assess its true epidemiology.

Immunohistochemical analysis of 36 cases of chondroblastomas: A single institutional experience

Chondroblastoma is a relatively uncommon, primary benign bone tumor, frequently identified in young individuals. Despite its classical radiologic and histopathological features, at times, it is fraught with a diagnostic challenge, especially differentiating it from a giant cell tumor of bone (GCTB); an osteosarcoma and a chondrosarcoma. Lately, few studies have shown the diagnostic utility of immunohistochemical (IHC) expression DOG1 antibody in chondroblastomas. The present study was undertaken to evaluate IHC expression of S100 protein, DOG1 and p63 in 36 chondroblastomas.From January 2013 to July 2019 (6-year duration), 106 chondroblastomas were diagnosed, with IHC staining performed in 36 cases. Conventional Hematoxylin and Eosin stained microsections and IHC stained sections were reviewed in 36 cases. IHC staining of p63 (intranuclear), S100 protein (nuclear and cytoplasmic) and DOG1 (cytoplasmic membranous) was recorded in various cases.Seventy-four tumors occurred in males and 32 in females, within age-range of 7–55 years (average = 18.6), frequently in tibia (33/106; 31.1%), followed by femur (26, 24.5%) humerus (22, 20.7%), calcaneum (5) and scapula (4). IHC staining for S100P was positive in 33/36cases (91.7%); DOG1 in 16/19 (84.2%) cases and p63 in 10/15cases (66.6%). DOG1 immunostaining was negative in 25 various other tumors. Sensitivity and specificity for S100P, DOG1and p63 in chondroblastomas was (91.6%, 59.3%); (84.2%, 100%) and (66.6%, 46.6%), respectively. P63 was positively expressed in 15/27 (55.5%) GCTBs.S100 protein and DOG1 can be utilized for a confirmatory diagnosis of a chondroblastoma, especially for differentiating it from its other differentials, such as GCTB, in view of certain associated therapeutic implications. P63 is not useful in that scenario.

Treatment and recurrence of giant cell tumors of bone - A retrospective cohort from a developing country.

IntroductionGCT is a benign primary bone tumor which is known to cause local recurrence as well as distant metastases. The standard care of treatment of GCT in our institution is the extended intralesional curettage followed by the use bone cement and either phenol or alcohol as adjunct therapy. This offers preservation of joint closest to tumor and decreased risk of recurrence compared to curettage alone. Therefore, the objective of this study was to assess the recurrence of GCT of the bone and time of recurrence-free survival after primary surgery (curettage with adjunct therapy) and determine the influence of factors like site of tumor involvement and demographic factors on the risk of recurrence.MethodsNon-funded, non-commercial single group retrospective cohort study was conducted at a tertiary care university hospital. Total of 44 patients treated for primary GCT of the bone between 1995 and 2015 at our institution were included. Medical record files were reviewed for demographic characteristics, intra-operative findings and post-operative follow-up. Risk factors for recurrence and mean recurrence free survival was calculated using appropriate statistical analysis.ResultsProximal tibia was the most commonly involved bone followed by distal femur, while intralesional curettage with either phenol or alcohol as adjunct was the most common primary treatment. Mean follow-up period for all patients was 52.1 ± 43.9 months. Out of the 46 tumors operated primarily at our institution, recurrence developed in eight (17.4%) cases. Extra-compartmental spread of tumor and tumor grade were identified to have a significant association with recurrence (P = 0.013 and 0.043 respectively). Estimated recurrence free survival at 2 and 5 - year interval was 0.85 and 0.83 respectively.ConclusionExtra-compartmental extension of tumor and a higher-grade lesion is significantly associated with development of recurrence in cases of GCT of bone.

Role of diffusion-weighted MRI in differentiating benign from malignant bone tumors.

Objective:To evaluate the role of diffusion-weighted MRI in differentiating benign from malignant primary bone tumors. To know the sensitivity and specificity of diffusion weighted MRI and calculating apparent diffusion coefficient (ADC) cutoff in differentiating benign from malignant primary bone tumors.Methods and materials :This is a prospective observational study of 50 patients, who were clinically or radiologically suspected with primary bone tumor and referred to the Department of Radiodiagnosis, for radiography or for MRI. These patients underwent routine MRI sequences including diffusion-weighted MRI with b-values of 0, 500 and 1000, followed by pathological examination supplemented by immunohistochemistry (wherever necessary). Hematological malignancies, recently biopsied cases and recurrent cases were excluded from the study.Results:Out of 50 patients with suspected bone tumors, 15 were benign (and tumor like lesions) and 35 were malignant primary bone tumors. The most common age group involved for both benign and malignant primary bone tumors was 11–20 years (23 cases—46%). In our study, total number of affected males were 27 (54%) and total number of affected females were 23 (46%) with M:F ratio of 1.17:1. In this study 72% lesions had appendicular bone involvement and 28% had axial bone involvement. 94.3% of malignant lesions showed restriction on diffusion-weighted imaging (DWI) and in 80 % of benign lesions restriction was absent on DWI which was statistically significant. Mean ADC levels in malignant lesions was 1.092 ± 0.497 and in benign lesions was 1.62 ± 0.596 which was statistically significant. Chondrosarcoma had highest ADC and Ewing’s sarcoma had lowest ADC values in malignant lesions. Chondroblastoma had highest ADC and Osteomyelitis had lowest ADC values in benign lesions. ADC value of 1.31 had highest sensitivity and specificity to differentiate between benign and malignant lesions.Conclusion:DWI is helpful in differentiating malignant from benign bone tumors and tumor like lesions with diffusion restriction favoring malignancy. Inspite of some overlap, ADC values of benign and malignant bone tumors are different and measurement of ADC values improves the accuracy of the diagnosis of bone tumors and tumor like lesions. Calculation of ADC may also be used as baseline reference to assess response to treatment in future or for follow up.Advances in knowledge:DWI imaging (and ADC values) has been extensively used in neuroimaging. Extension of this application to musculoskeletal–oncologic imaging is not so well studied. Apart from differentiating benign from malignant lesions which is the main focus of this study, assessment of response to treatment by ADC values may be possible in near future.

Challenges of denosumab in giant cell tumor of bone, and other giant cell-rich tumors of bone.

Purpose of reviewGiant cell tumor of bone (GCTB) is an uncommon benign primary bone tumor, consisting of receptor activator of nuclear factor kappa-B (RANK) expressing reactive osteoclast-like giant cells and neoplastic spindle-shaped cells. Denosumab was approved by FDA in 2013 and by EMA in 2014 to treat adults and skeletally mature adolescents with unresectable GCTB or when resection is likely to result in severe morbidity. However, there is much discussion regarding the optimal applied treatment strategy.Recent findingsNeoadjuvant treatment of GCTB with denosumab can effectively downstage tumors to facilitate less morbid surgery or completely avoid the need for resection, but there is concern about local recurrence postsurgery. Definitive treatment of unresectable GTCB improves symptoms and halts tumor progression. The optimal treatment duration is unclear and long-term treatment is associated with adverse events like osteonecrosis of the jaw (ONJ) and atypical femoral fractures. Denosumab maintenance dose interval is currently being investigated.SummaryFor the related but heterogenous group of giant cell rich tumors of bone, like aneurysmal bone cysts (ABC) and central giant cell granuloma (CGCG), denosumab is a new treatment modality under investigation. Given the effectiveness in GCTB, this could be a promising treatment option for selected patients with advanced disease.