Giant Cell Tumor of Bone: Review, Mimics, and New Developments in Treatment

Conventional radiography for the assessment of focal bone lesions of the appendicular skeleton: fundamental concepts in the modern imaging era

Bone lesions of the appendicular skeleton can be caused by primary benign or malignant tumors, metastases, osteomyelitis, or pseudotumors. Conventional radiography plays a crucial role in the initial assessment of osseous lesions and should not be underestimated even in this era of modern complex and advanced imaging technologies. Combined with patient age, clinical symptoms and biology, and lesion features including location, solitary versus multiplicity, density, margin (transitional zone evaluated with Lodwick-Madewell grading score), and, if present, the type of periosteal reaction and matrix mineralization can narrow the differential diagnosis or offer a likely diagnosis. These radiographic features help guide further follow-up or management.

Giant cell tumor of bone of temporal bone and skull base: report of 6 cases

OBJECTIVE

Five cases of giant cell tumor of bone (GCTB) in the head and neck region were reported, with a main focus on the radiological findings to identify common characteristics for the diagnosis of GCTB in these sites.

MATERIALS AND METHODS

Five consecutive patients diagnosed with GCTB were retrospectively selected. Radiological features on conventional and advanced MR sequences and CT were analyzed. HE staining and immunohistochemical examination were performed using antibodies against p63 and CD68.

RESULTS

The common clinical features were local mass (3/5), tinnitus (3/5) and headache (2/5). Radiologically, all the cases were well-circumscribed osteolytic lesion, majority of cases demonstrated an expansile growth pattern and "soap bubble" appearance on CT (4/5). On MRI, the tumors showed predominantly hypointensity both on T1WI and T2WI, and no evidence of restricted diffusion on DWI. Intratumoral hemorrhage (2/5), cystic alternation (2/5) and very low signal on T2WI in the periphery region of the tumor (4/5) was found. Fluid-fluid level was noted in one case, which was eventually verified to be GCTB with secondary aneurysmal bone cyst (ABC). With contrast agent, all the cases showed striking (3/5) or mild to intermediate (2/5) enhancement.

CONCLUSIONS

Although the above described radiological findings are not specific for GCTB in head and neck region, a well-defined osteolytic lesion in the bones of head and neck region with "soap bubble" appearance on CT and hypointensity on T2WI with very low signal in the peripheral region of the tumor on MRI highly suggest GCTB for patient ages 20 to 40.

18F-FDG PET/CT in a Giant Cell Tumor of Bone Masquerading as a Retroperitoneal Soft Tissue Sarcoma

Giant cell tumor of bone (GCTB) is a rare, benign but locally aggressive neoplasm that typically arises in the epiphysis of long bones. GCTB occurrence in the axial skeleton is less common. Due to its variable radiological appearance and unusual location, GCTB can be misdiagnosed as a soft tissue or retroperitoneal mass, leading to delays in diagnosis and inappropriate treatment. We present the case of a 36-year-old woman who was misdiagnosed as a case of spinal tuberculosis and was started on ATT. Initial imaging, including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), revealed a large, retroperitoneal mass involving the L2 vertebral body, raising suspicion of a malignant soft tissue tumor. Further evaluation with 18F-FDG PET/CT suggested a retroperitoneal metabolically active lesion, reinforcing the need for histopathological confirmation.

Spinal giant cell tumour presenting as a posterior mediastinal mass

Posterior mediastinal masses frequently originate from neurogenic tumours; however, other possible causes include vascular abnormalities, cysts and primary bone tumours. We present a case involving a man in his 20s who experienced back pain, sudden sensorimotor weakness in both lower limbs and loss of bladder control. Imaging studies, including CT and MRI, identified a posterior mediastinal extramedullary mass associated with vertebral destruction and intrathecal extension. A biopsy of the mass confirmed it to be a giant cell tumour of bone. The patient was treated with denosumab, steroids and spinal decompression and was scheduled for definitive surgery. In young individuals presenting with a posterior mediastinal mass, signs of inflammation and early neurological symptoms, it is essential to consider primary bone tumours as a possible diagnosis.

DENO Research Group, de la Calva C, Angulo M, González-Rojo P, Peiró A, Machado P, Cebrián JL, García-Maroto R, Valcárcel A, Puertas P, Valero-Cifuentes G, Pablos Ó, Maireles M, Fontalva ML, Chaves I, Orce A, Coll-Mesa L, Pérez I, González F, Sanz MDC, Gracia I. A Multicenter Study by the DENO Research Group on the Use of Denosumab in Giant-Cell Tumors of the Bone

Background/Objectives: Despite the therapeutic potential of denosumab for the treatment of giant-cell tumors of the bone (GCTBs), there is a lack of standardization in treatment protocols. Methods: We present a multicenter, retrospective, descriptive study conducted across the seven hospitals in Spain affiliated with the DENO Research Group. Seventy-three patients diagnosed with GCTB and treated with denosumab were included and stratified according to treatment strategy-neoadjuvant (n = 38), adjuvant (n = 8), and single treatment (n = 27). Results: Patients in the neoadjuvant group received denosumab for a median of 6.1 months, with reintroduction after surgery in 25.8% of all cases. Among the neoadjuvant patients treated with curettage, recurrence was 35.5%, with no association with denosumab treatment duration (p = 0.274) nor with denosumab reintroduction after surgery (p = 0.405). In the adjuvant group, those who completed treatment received denosumab for 15.3 months, while those still undergoing therapy received it for a median of 12.8 months; only one case (12.5%) recurred. Recurrence rates in neoadjuvant and adjuvant treatment strategies were not different (p = 0.394). Patients treated only with denosumab and no longer on treatment had received it for 34.2 months, with 31.3% recurrence; those still on treatment had received it for 51.8 months, with 25.0% recurrence. Across all strategies, more than 85% of patients reported favorable clinical outcomes, and only 43.8% presented adverse events. No deaths occurred during this study. Conclusions: Although patients who experienced recurrence during neoadjuvant treatment had longer durations of denosumab administration, the difference was not statistically significant. Similarly, recurrence rates did not differ significantly, whether denosumab was reintroduced after surgery or not. Among the patients treated with curettage, recurrence rates were comparable between neoadjuvant and adjuvant strategies. Discontinuation of the single treatment did not necessarily result in disease progression.

Capillary telangiectatic osteosarcoma misdiagnosed as aneurysmal bone cyst in a 12-year-old girl: A case report

INTRODUCTION AND IMPORTANCE

Telangiectatic osteosarcoma (TOS) is a rare and aggressive subtype of osteosarcoma that is often misdiagnosed as more benign lesions, such as aneurysmal bone cysts (ABCs) or giant cell tumors (GCTs). The accurate differentiation between these conditions is crucial to ensure timely and appropriate treatment, as misdiagnosis can lead to delayed management and poor prognoses.

CASE PRESENTATION

We present the case of a 12-year-old girl who initially presented with left hip and proximal thigh pain, with imaging studies suggesting an ABC. Following curettage and grafting, the initial pathology report confirmed the diagnosis of ABC. However, the patient experienced rapid recurrence within two months, leading to further surgical intervention. A thorough re-evaluation of the pathological specimen revealed characteristics consistent with TOS, confirmed by immunohistochemical staining and molecular tests. The patient received four cycles of chemotherapy after the second surgery and underwent limb - salvage surgery 3 months after the operation.

CLINICAL DISCUSSION

This case highlights the challenges in diagnosing TOS due to its histological similarity to other giant cell-rich lesions. The initial misdiagnosis delayed the commencement of appropriate treatment. However, upon correct identification, the patient was treated with an effective chemotherapy regimen, including cisplatin, doxorubicin, and ifosfamide, resulting in significant tumor regression and control of lung metastases.

CONCLUSION

This case underscores the necessity for clinicians to maintain a high index of suspicion for TOS when evaluating aggressive bone lesions, particularly in pediatric patients. The importance of comprehensive pathological assessment, including immunohistochemistry and molecular analysis, cannot be overstated, as early and accurate diagnosis significantly influences treatment outcomes and prognosis.

Investigating the Challenges in Diagnosis and Management of Giant Cell Tumors in the Distal Phalanx: A Case Report

Giant cell tumors (GCTs) of bone are locally aggressive neoplasms that typically occur in the distal femur or proximal tibia. Infrequently, they may develop in the bones of the hand, including the distal phalanx. This case highlights the importance of a thorough and systematic diagnostic workup of GCTs presenting in rare and challenging locations such as the distal phalanx. A 53-year-old male presented to the clinic with a several-month history of left middle fingertip enlargement, pain, and limited mobility. Plain film X-ray and magnetic resonance imaging revealed a lesion in the left middle distal phalanx. The patient underwent curettage with a working diagnosis of giant cell reparative granuloma with focal fracture callus. Eight months later the mass recurred and amputation of the distal phalanx tip was performed. The histopathological evaluation confirmed a diagnosis of a giant cell tumor of bone. The postoperative course was unremarkable. No further treatment was required. In rare and difficult-to-diagnose tumors clinicians should consult with experienced pathologists to improve diagnostic accuracy. This approach is essential for optimizing patient outcomes, preventing treatment delays, and reducing the risk of adverse events.

Bone tumors: a systematic review of prevalence, risk determinants, and survival patterns

BACKGROUND

Though relatively rare, bone tumors significantly impact patient health and treatment outcomes.

OBJECTIVE

This systematic review analyzes the incidence, types, survival rates, and risk factors associated with bone tumors, including both benign and malignant forms.

METHODS

This systematic review was conducted using the keywords "bone tumors," "epidemiology," "benign bone tumors," "malignant bone tumors," "osteosarcoma," "Ewing sarcoma," "chondrosarcoma," "risk factors," and "survival" in electronic databases including PubMed, Scopus, Web of Science, and Google Scholar from 2000 to 2024. The search strategy was based on the PRISMA statement. Finally, 9 articles were selected for inclusion in the study.

RESULTS

The systematic review highlights that primary bone tumors can be classified into benign and malignant types, with osteosarcoma being the most prevalent malignant form, particularly among adolescents and young adults. The epidemiology of bone tumors is influenced by factors such as age, gender, geographic location, and genetic predispositions. Recent advancements in imaging techniques have improved the detection of these tumors, contributing to an increasing recognition of their prevalence. Data shows that the limited-duration prevalence of malignant bone tumors has increased significantly. This increase is from 0.00069% in 2000 to 0.00749% in 2018, indicating an increasing recognition and diagnosis of these rare tumors over time. Survival rates vary significantly by tumor type, with approximately 50-60% for osteosarcoma and around 70% for Ewing's sarcoma, though these rates decrease with metastasis. Key risk factors identified include genetic predispositions such as Li-Fraumeni syndrome and TP53 mutations, environmental exposures like radiation, and growth patterns related to height.

CONCLUSION

The review highlights the importance of early diagnosis and treatment intervention, as survival rates are significantly better for patients with localized disease compared to those with metastatic conditions. The observed variations in survival rates across different tumor types underscore the need for tailored treatment strategies. Key risk factors include genetic predispositions and environmental exposures, highlighting the need for targeted screening and ongoing research to enhance diagnostic accuracy and treatment strategies.

Management and surveillance of metastatic giant cell tumour of bone

Giant cell tumour of bone (GCTB) is viewed as a benign, locally aggressive primary bone tumour with metastatic potential. Current management is surgery with bone curettage or resection and systemic therapy with denosumab. Diagnosis is confirmed histologically prior to surgery, with staging for pulmonary disease, as pulmonary metastases (PM) reportedly occur in <8%. This study aimed to assess incidence, surveillance and management of PM in patients with GCTB, with histopathological review. A retrospective audit of the Oxford bone tumour registry was performed from January 2014 - October 2023. Inclusion criterion was histological confirmation of GCTB. Exclusion criteria were incomplete medical, imaging or histology records, or referral for secondary MDT opinion for diagnosis. From an initial group of 126 GCTB patients, 83 patients met the full selection criteria. Pulmonary metastases were identified in 11 patients. Three with PM were excluded on histopathological review as being giant cell rich osteosarcoma rather than metastatic GCTB. This left 8 (9.6%) patients, one had PM at presentation and seven at follow-up between 2 and 42 months. Two were histologically confirmed after cardiothoracic surgery and biopsy, six radiologically diagnosed. Three (37.5%) patients with PM have died (between 1 and 12 months after confirmed PM), five are alive with stable disease. Seven (87.5%) of patients with pulmonary disease were treated with denosumab/chemotherapy (three before, four after pulmonary diagnosis). Five (62.5%) with pulmonary disease had recurrence of local disease requiring further surgery. Local recurrence was an independent risk factor for PM on statistical analysis. GCTB may present with PM, but more commonly, metastasis occurs after surgery, presenting on surveillance and can progress. There were no distinct differences in histopathological appearance between patients with GCTB that developed PM and those that did not, therefore morphological features of the tumour cannot be currently used to predict tumour behaviour. PM can behave aggressively, necessitating identifying histological markers to recognise patients at risk of metastatic GCTB, for example, through mRNA single cell analysis. We propose GCTB patients with PM receive regular chest surveillance with PET scan and/or CT to monitor disease progression, and a multi-centre audit of GCTB outcome undertaken to further define optimal clinical management.

Case report: A rare case of chondrosarcoma-like malignant giant cell tumor in adolescent rib: diagnostic challenges and treatment

Chondrosarcoma-like malignant giant cell tumor (GCT) of the rib is an extremely rare and aggressive tumor, particularly in adolescents. This case report describes a 19-year-old female presenting with a GCT of the rib with chondrosarcomatous differentiation, highlighting the challenges posed by its unusual location and pathological complexity. Multidisciplinary diagnostic approaches, including advanced imaging, immunohistochemistry (IHC), and pathology, were essential for confirming the diagnosis. Key IHC markers such as Vimentin, SMA, and CD163, alongside genetic analysis excluding H3F3A mutations, guided the diagnostic process. The patient underwent successful surgical resection, achieving early recovery without adjuvant therapy. This report underscores the importance of early detection, precise pathological evaluation, and individualized surgical treatment for rare and high-risk tumors, emphasizing the need for long-term follow-up to monitor recurrence.

Giant cell tumor of the talus: A case report and literature review

INTRODUCTION AND IMPORTANCE

Giant cell tumor is a benign primary bone tumor of mesenchymal origin that mainly affects the long bones. Involvement of the bones of the foot is rare with an incidence of 1 to 2 %. We report a case of giant cell tumor of the talus in a 36-year-old man.

CASE PRESENTATION

A 36-year-old tailor with no past medical history presented with pain in the left ankle. The symptoms had been present for approximately three years. A small, non-inflammatory swelling was observed on the anteromedial side of the ankle. The range of motion of the ankle was normal and painless in all planes. X-rays of the ankle revealed a well-defined lytic lesion at the neck of the talus without periosteal reaction. An MRI was performed, revealing a lytic pattern in the inner half of the talus, which expanded and thinned the cortex without obvious signs of breakthrough. The diagnosis was confirmed by a biopsy, which revealed a giant cell tumor of the talus without any signs of malignancy. Surgical treatment by tibiocalcaneal arthrodesis was performed.

CLINICAL DISCUSSION

Giant cell tumor is a benign tumor that usually occurs in long bones in 85 % of cases, with 10 % of cases reported in the axial skeleton. Its location in the bones of the foot is uncommon, with an incidence ranging from 1 to 2 %.

CONCLUSION

Giant cell tumor is a benign but locally aggressive tumor. Talectomy associated with arthrodesis is a viable therapeutic alternative for extensive destructive lesions.

DENO Research Group, de la Calva C, Angulo M, González‐Rojo P, Peiró A, Machado P, Cebrián JL, García‐Maroto R, Valcárcel A, Puertas P, Valero‐Cifuentes G, Pablos Ó, Maireles M, Fontalva ML, Chaves I, Orce A, Coll‐Mesa L, Pérez I, González F, del Carmen Sanz M, Gracia I. Do Unresectable Giant Cell Tumors of Bone Treated With Denosumab Progress After Discontinuation of Treatment?

BACKGROUND

Denosumab represents a valuable treatment option for unresectable giant cell tumors of the bone (GCTBs). However, no standardized protocols exist determining the length of administration, with few studies having been published on patients who reached the end of treatment.

AIMS

To analyze the outcomes of patients diagnosed with GCTB and who had finished single treatment with denosumab.

METHODS AND RESULTS

This is a multicenter, retrospective, descriptive study carried out in seven Spanish hospitals with multidisciplinary sarcoma and musculoskeletal tumor boards, between 2009 and 2019. Sixteen patients diagnosed with unresectable GCTBs and treated with denosumab who had reached the end of their treatment were recruited for the study and had been followed up for a minimum of 2 years. Fifty percent of patients discontinued denosumab after showing signs of tumor control. The disease remained stable in 69% of patients (n = 11), with a median recurrence-free survival time of 46 months (20-157 months) after being treated for a median period of 19 months (5-83 months). Four patients experienced local progression, and one presented multifocal progression. These five patients were treated for a median period of 46 months (14-76 months), with a median recurrence-free survival time of 9 months (5-25 months).

CONCLUSION

The findings of the present study suggest that discontinuation of denosumab in patients with unresectable GCTB is not necessarily associated with the progression of the disease. Further research is needed to determine how long denosumab should be administered to minimize the risk of recurrence.

Giant cell tumour of the larynx-a diagnostic challenge

Giant cell tumours (GCTs) of the larynx are extremely rare. The most affected structure is the thyroid cartilage and only 44 cases are reported in the literature.1 Clinically, their first manifestation is usually a palpable neck mass, often accompanied by hoarseness, dyspnoea, and/or dysphagia depending on size and location. GCTs are benign neoplasms, yet awareness of this entity is crucial as their aggressive local behaviour can cause significant morbidity with airway obstruction and can simulate a malignancy. The differential diagnosis is broad and remains a clinical and radiological challenge. Indeed, the final diagnosis is established by histology postoperatively. Surgery is the preferred treatment but may impair voice quality. For incomplete surgical resections and high surgical risk lesions, denosumab treatment is a valuable option. We share our experience on GCTs in a young adult presenting as a supraglottic mass.

Giant cell tumor of the cervical spine: A case report

INTRODUCTION

A Giant Cell Tumor (GCT) of the bone is a locally osteolytic tumor made up of mononuclear ovoid stromal cells and multinucleated giant cells. It commonly affects long bones like the distal femur and proximal tibia, but can also develop in the cervical spine during the third and fourth decades of life.

PRESENTATION OF CASE

A 20-year-old female presented to the clinic with a complaint of neck pain persisting for one month. Clinical examination revealed bilateral radiculopathy in the upper limb, which was also associated with pain in the left shoulder and elbow. Imaging revealed a destructive lesion in the 7th cervical vertebra (C7). A biopsy was done which indicated a giant cell tumor (GCT). A C7 corpectomy was performed, which included the removal of the C7 vertebral body and application of a cage. At the two-year follow-up, the patient remained asymptomatic, and radiographs showed no signs of recurrence.

DISCUSSION

A Giant Cell Tumor (GCT) occurring above the sacrum, especially in the cervical spine, is extremely rare. Symptoms of GCT are often nonspecific and can include neck pain, numbness, and weakness in the upper limbs, which are sometimes mistaken for myalgia or disc disease. The main treatment goal for GCT is "en bloc" resection while preserving the joint, though this can be challenging, particularly in spinal cases.

CONCLUSION

It is crucial to acknowledge that GCT can appear in uncommon sites and age groups. Surgeons must have a high level of awareness and perform an adequate preoperative workup, before definitive treatment. The patient should undergo regular follow-ups to detect any recurrence or metastasis at an early stage.

Measurable progression of giant cell tumour of bone associated with pregnancy - A tertiary sarcoma centre analysis

Introduction

Giant cell tumour of bone (GCTB) is a benign but locally aggressive bone tumour with a higher predilection for females of reproductive age. GCTB management poses a unique set of challenges during pregnancy due to risks associated with imaging and treatment options. Pregnancy has been implicated in GCTB progression and tumour recurrence, however an exact mechanism has not been established. This study aims to confirm the relationship between the diagnosis and progression of GCTB during pregnancy.

Methods

A 17-year retrospective analysis of our tertiary sarcoma referral centre database was performed to identify the relevant patients. Pregnancy-associated tumours were defined by those already present or diagnosed during pregnancy, and up to 12 months postpartum. Lesion volume was determined by mathematical ellipsoidal modelling technique to simplify the estimation, with cross-sectional measurements obtained from the three standard orthogonal planes on initial and surveillance imaging. Due to logistical challenges, follow-up imaging was performed at either our tertiary sarcoma centre or under guidance at regional imaging centres convenient to the patient.

Results

The diagnosis of GCTB was made in 113 female patients during this 17-year period, of which 20 were associated with pregnancy with a mean age of 28.8 years (range 19-40 years). 12 patients had their primary or recurrent GCTB diagnosed, or known tumour progress during pregnancy, whilst the remaining 8 were diagnosed shortly thereafter to within 12 months postpartum. The most common tumour sites were located around the knee (30 %) and distal radius (25 %). A statistically significant pattern of growth was observed through the surveillance period (p 0.018), within a relatively short mean follow-up period of only 89.8 days (SD 54.5; 13-192 days).

Conclusion

This study demonstrates the significant association that pregnancy has with the growth and progression of both primary and recurrent GCTB. Pregnant patients should be subject to close surveillance well into the postpartum period due to possible accelerated disease progression and potential for disease recurrence.

Locking plate augmentation of polymethylmethacrylate-filled distal femoral defects: A biomechanical study

Benign, locally aggressive tumors of the distal femur are typically treated with intralesional curettage and polymethylmethacrylate (PMMA) cementation. However, it is not known whether plate fixation should be added to biomechanically augment these PMMA-filled defects. The purpose of this study was to evaluate the performance of two competing techniques for reconstruction of a distal femoral defect. For this biomechanical study, we used 12 composite femurs with properties comparable to bone. In nine femurs, identical contained medial distal femoral defects were created using a robotic arm. Group A contained three intact femurs, Group B three femurs with an unfilled defect, Group C three femurs reconstructed with PMMA alone, and Group D three femurs reconstructed with PMMA plus a medial locking plate. Locations of greatest stress concentration were determined by PhotoStress analysis, then three strain gauges were applied to each specimen at these high-stress locations. Specimens were loaded within a physiologic range followed by loading to failure. Outcome measures included construct stiffness, strain along the distal femur, and load at failure. Results showed that stiffness and strain were not significantly different between reconstructive techniques; however, both techniques reduced tensile strain along the popliteal surface by approximately 40% compared to non-reconstructed specimens. All specimens failed at the femoral neck before failing at the distal femur. These findings suggest that plate augmentation of PMMA-filled distal femoral defects like the one in this study offers insignificant biomechanical benefit within physiologic loads and therefore may be unnecessary.

Management of Giant Cell Tumor of Distal Radius-Does Curettage Work?

Giant cell tumor affecting distal radius has been considered more aggressive, as compared to its counterparts in other locations. While resection has been advocated as the treatment of choice with lower rates of recurrence, curettage has reportedly led to superior functional outcomes. This retrospective study aimed to evaluate the functional and oncological outcomes of patients managed for GCT distal radius by either extended intralesional curettage (EIC) or resection and arthrodesis with radialisation of ulna (RRU), with respect to rates of local recurrence and function. Twenty-four patients operated for giant cell tumor of distal radius by a single surgeon from 2011 to 2021, were included in the study. The demographic, clinico-radiological, and surgical details were recorded and analyzed, as were the functional and oncological outcomes. At a median (IQR) follow-up of 6.3 years (range 2 years to 15.9 years), the rate of recurrence in curettage was found to be higher than that in resection but was not statistically significant (35.7% vs 20%, p > 0.05). Patients managed elsewhere and then presented to us for recurrence had a higher rate of local recurrence (66.6%, p = 0.01). Average time to recurrence was 14 months (range 2-24 months). On final follow-up, patients in curettage group had better functional outcomes in terms of grip strength and range of motion. Mean Modified Mayo Wrist score and MSTS score were 78.2 and 25.63, respectively, for EIC group and 69.6 and 25.75, respectively, for RRU group. Extended intralesional curettage resulted in an earlier rehabilitation with a mobile wrist and acceptable disease control when compared with resection and arthrodesis with radialisation of ulna.

Case 328: Brown Tumor in Hyperparathyroidism Due to Parathyroid Adenoma

HISTORY

A 45-year-old female patient with diffuse osteoarticular pain, particularly low back pain, was referred by a rheumatologist for an updated radiologic evaluation. The patient had experienced these symptoms for many years and was diagnosed with human leukocyte antigen B27-negative spondyloarthritis approximately 11 years prior, based on findings of bilateral erosive sacroiliitis at pelvic radiography and bone scintigraphy with technetium 99m (99mTc) methylene diphosphonate. After 3 years of treatment with a tumor necrosis factor-α inhibitor (adalimumab), which was effective for pain, the patient was lost to follow-up. At the current presentation, approximately 8 years after being lost to follow-up, the patient presented with worsening low back pain. The presence of nonobstructing kidney stones on US images confounded the underlying cause of worsening pain. The patient also experienced fatigue and depressed mood. Routine blood tests revealed a normal blood cell count, creatinine level of 0.64 mg/dL (56.58 μmol/L) (normal range, 0.30-1.1 mg/dL [26.52-97.24 μmol/L]), C-reactive protein level of 1.1 mg/dL (normal, <1 mg/dL), and vitamin D level of 21 ng/mL (52.42 nmol/L) (normal range, 30-100 ng/mL [74.88-249.60 nmol/L]). Noncontrast MRI of the thoracic and lumbar spine, MRI of the sacroiliac joints, and CT of the abdomen and pelvis were performed.

A radiograph-based deep learning model improves radiologists' performance for classification of histological types of primary bone tumors: A multicenter study

PURPOSE

To develop a deep learning (DL) model for classifying histological types of primary bone tumors (PBTs) using radiographs and evaluate its clinical utility in assisting radiologists.

METHODS

This retrospective study included 878 patients with pathologically confirmed PBTs from two centers (638, 77, 80, and 83 for the training, validation, internal test, and external test sets, respectively). We classified PBTs into five categories by histological types: chondrogenic tumors, osteogenic tumors, osteoclastic giant cell-rich tumors, other mesenchymal tumors of bone, or other histological types of PBTs. A DL model combining radiographs and clinical features based on the EfficientNet-B3 was developed for five-category classification. The area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity were calculated to evaluate model performance. The clinical utility of the model was evaluated in an observer study with four radiologists.

RESULTS

The combined model achieved a macro average AUC of 0.904/0.873, with an accuracy of 67.5 %/68.7 %, a macro average sensitivity of 66.9 %/57.2 %, and a macro average specificity of 92.1 %/91.6 % on the internal/external test set, respectively. Model-assisted analysis improved accuracy, interpretation time, and confidence for junior (50.6 % vs. 72.3 %, 53.07[s] vs. 18.55[s] and 3.10 vs. 3.73 on a 5-point Likert scale [P < 0.05 for each], respectively) and senior radiologists (68.7 % vs. 75.3 %, 32.50[s] vs. 21.42[s] and 4.19 vs. 4.37 [P < 0.05 for each], respectively).

CONCLUSION

The combined DL model effectively classified histological types of PBTs and assisted radiologists in achieving better classification results than their independent visual assessment.

Neoplastic and Non-neoplastic Bone Lesions of the Knee

Numerous anatomical variants are described around the knee, many of which look like bony lesions, so it is important to know them to avoid unnecessary complementary tests and inadequate management. Likewise, several alterations in relation to normal development can also simulate bone lesions.However, numerous pathologic processes frequently affect the knee, including traumatic, inflammatory, infectious, and tumor pathology. Many of these entities show typical radiologic features that facilitate their diagnosis. In other cases, a correct differential diagnosis is necessary for proper clinical management.Despite the availability of increasingly advanced imaging techniques, plain radiography is still the technique of choice in the initial study of many of these pathologies. This article reviews the radiologic characteristics of tumor and nontumor lesions that may appear around the knee to make a correct diagnosis and avoid unnecessary complementary radiologic examinations and inadequate clinical management.

Keratin-Positive Giant Cell-Rich Tumor: A Review and Update

Keratin-positive giant cell-rich tumor (KPGCT) is an extremely rare and recently described mesenchymal neoplasm that occurs in both soft tissue and bone, frequently found in young women. It has locally recurrent potential if incompletely excised but low risk for metastasis. KPGCT is histologically similar to conventional giant cell tumors of soft tissue but shows the presence of keratin-positive mononuclear cells. Interestingly, KPGCT also shares some morphological features with xanthogranulomatous epithelial tumors. These two tumors have recently been shown to harbor an HMGA2-NCOR2 fusion, arguing in favor of a single entity. Surgery is the treatment of choice for localized KPGCT. Therapeutic options for advanced or metastatic disease are unknown. This review provides an overview of the current knowledge on the clinical presentation, pathogenesis, histopathology, and treatment of KPGCT. In addition, we will discuss the differential diagnosis of this emerging entity.

Microwave-assisted intralesional curettage combined with other adjuvant methods for treatment of Campanacci III giant cell tumor of bone in distal radius: a multicenter clinical study

Objective

To compare the clinical outcomes of microwave-assisted intralesional curettage(MAIC) with those of en bloc resection and autogenous fibular reconstruction (EBR-AFR) for treating grade III giant cell tumor of the bone (GCTB) of the distal radius and to elucidate the indications for wrist preservation surgery.

Materials and methods

In this retrospective study, 19 patients with grade III GCTB of the distal radius who underwent surgery at three medical institutions were included and categorized based on their surgical pattern. Seven patients underwent MAIC and internal fixation with bone cement (MAIC group) and 12 underwent EBR-AFR (EBR-AFR group). To evaluate the function of the affected limb postoperatively, wrist range of motion, grip strength, Musculoskeletal Tumor Society (MSTS) scores were recorded.

Results

The follow-up time of the MAIC group was 73.57 ± 28.61 (36-116) months, with no recurrence or lung metastasis. In contrast, the follow-up time of the EBR-AFR group was 55.67 ± 28.74 (36-132) months, with 1 case of local recurrence (8.3%, 1/12) and 1 case of lung metastasis (8.3%, 1/12). The wrist flexion, extension, supination, pronation, grip strength were better in the MAIC group than in the EBR-AFR group. Although there was no statistically significant difference in the MSTS score between the two groups, it is noteworthy that the MAIC group exhibited significantly superior emotional acceptance and hand positioning compared to the EBR-AFR group(p < 0.05).

Conclusion

The functional outcomes of the MAIC group are better. The treatment strategy for grade III GCTB of the distal radius should be determined based on the specific preoperative imaging findings. Nevertheless, MAIC can be the preferred surgical approach for most patients with grade III GCTB of the distal radius, particularly for young patients.

Keratin-Positive Giant Cell-Rich Tumor of Bone Harboring an HMGA2::NCOR2 Fusion: Two Cases, Including a Patient With Metastatic Disease, and Review of the Literature

Giant cell-rich lesions of bone represent a heterogeneous group of entities which classically include giant cell tumor of bone, aneurysmal bone cyst, nonossifying fibroma, and Brown tumor of hyperparathyroidism. A recently described subset of giant cell-rich tumors involving bone and soft tissue has been characterized by recurrent HMGA2::NCOR2 fusions and keratin expression. The overlapping clinical, radiographic, and morphological features of these giant cell-rich lesions provide a unique diagnostic challenge, particularly on biopsy. We present 2 additional cases of keratin-positive giant cell-rich tumor of bone with HMGA2::NCOR2 fusions, including 1 patient who developed metastatic disease.

Giant Cell Tumor of the Anterior Arc of the Rib: A Case Report

Tumors that develop on the chest wall are usually rare. This case report highlights a rare occurrence of a giant cell tumor originating from the anterior arch of the fourth rib. The patient, a 21-year-old male, presented with a bulging mass that had been gradually increasing in size over an eight-month period, reaching dimensions of 12 x 8 cm. Despite the noticeable swelling, the patient reported no associated pain or discomfort and denied any history of weight loss or trauma. The absence of chest pain or cardiovascular symptoms distinguished this case from other chest wall pathologies. This report underscores the importance of considering rare entities such as giant cell tumors in the differential diagnosis of chest wall masses, especially in cases where clinical presentation and patient history do not align with more common conditions.

Management of Recurrent Giant Cell Tumor of Distal Tibia With Intramedullary Hindfoot Fusion Nail and Trabecular Metal Implant Construct

Reconstruction options for giant cell tumors (GCTs) of bone are limited and challenging due to the amount of structural compromise and the high recurrence rates. This is especially true for GCTs of the foot and ankle, as the area is vital for weight bearing and function. The typical treatment for GCTs is currently excision, curettage, and cementation, although that is not always effective. A 36-year-old otherwise healthy female presented with an original diagnosis of a large aneurysmal bone cyst (ABC) of the distal tibia that had recurred despite two previous attempts at treatment with resection and cementation. She was treated with surgical resection of the lesion, reconstruction, and ankle and subtalar joint arthrodesis with a tibiotalocalcaneal intramedullary nail in combination with a trabecular metal cone. The final pathology of the intraoperative samples was consistent with GCT. Postoperatively, she recovered well, and her imaging was consistent with a successful fusion. This case report provides evidence that tibiotalocalcaneal fusion with a unique combination of hindfoot nail and trabecular metal cone construct in a single procedure is a successful option for the treatment of large, recurrent GCT lesions in the distal tibia.

A case report on pulmonary metastasis of giant cell tumor mimicking arteriovenous malformation

Giant cell tumor (GCT) is typically a benign tumor of the skeletal system that mainly presents with bone pain. Pulmonary metastasis is one of the distant presentations of GCT in patients who have previously undergone surgical resection of the tumor. Among the various presentations of pulmonary metastasis in GCT, lesions with arteriovenous malformation (AVM) features are rare and have only been reported in a few cases. In this case report, we present the case of a 29-year-old female patient who had previously undergone surgical resection of a GCT in her right lower extremity 4 years ago. The patient was referred to us with progressive dyspnea, and a lesion resembling an AVM was found during radiologic evaluation using chest computed tomography. Pathologic evaluation of the lesion after biopsy revealed that it was a metastasis of GCT presenting with vascular-like features in the lung. This study reports on a very rare occurrence of GCT pulmonary metastasis with an AVM appearance on imaging, highlighting the clinical importance of atypical presentations of pulmonary metastasis in patients with a history of GCT. Appropriate and timely screening and management of such lesions may prevent adverse outcomes such as massive hemorrhage and deterioration of lung function.

Denosumab combined with precision radiotherapy for recurrent giant cell tumor of the thoracic spine: a case report and literature review

Giant cell tumors of the spine have a high recurrence rate owing to their special anatomical site; hence, further treatment after recurrence is very challenging. Achieving effective tumor control and improving the long-term quality of life of the patients are the main treatment purposes to consider for recurrent giant cell tumors of the spine. A patient showing giant cell tumor recurrence of the thoracic spine after curettage received denosumab combined with precision radiotherapy, through which the tumor gained good control and the patient could regain normal functioning. A review of the relevant literature suggested that denosumab combined with radiotherapy is an effective new approach for the treatment of recurrent giant cell tumors of the spine.

[Giant cell tumor of bone-an update]

In the past few years, numerous new insights have been gained in the field of giant cell tumor of bone (GCTB). On the one hand, the detection of the highly characteristic histone mutation in the H3F3A gene in GCTB is becoming increasingly important in diagnostics in differentiating GCTB from other giant cell-rich lesions of bone as well as for defining rare variants of GCTB without osteoclastic giant cells. On the other hand, the effects of the H3F3A mutation were shown to have an impact on the epigenetic profile of tumor-driving stromal cells, providing new insights into tumorigenesis of GCTB.

Giant cell tumor of bone in the pediatric population: a retrospective study highlighting cases of metaphyseal only location and increased local recurrence rates in skeletally immature patients

OBJECTIVE

To describe the presentation of giant cell tumors (GCT) of the bone in the pediatric population to (1) improve the differential diagnosis of pediatric bone tumors and (2) identify the origin of GCT. Understanding the origin of bone tumors assists in establishing appropriate diagnoses and recommending treatment options. This is particularly important in children, where evaluating the need for invasive procedures is balanced with the desire to avoid overtreatment. GCT have historically been considered epiphyseal lesions with potential metaphyseal extension. Therefore, GCT may be inappropriately excluded from the differential diagnosis of metaphyseal lesions in the skeletally immature.

MATERIALS AND METHODS

We identified 14 patients from 1981 to 2021 at a single institution who had histologic confirmation of GCT and were less than 18 years old at diagnosis. Patient characteristics, tumor location, surgical treatment, and local recurrence rates were collected.

RESULTS AND CONCLUSIONS

Ten (71%) patients were female. Eleven (78.6%) were epiphysiometaphyseal (1 epiphyseal, 4 metaphyseal, 6 epiphysiometaphyseal). Five patients had an open adjacent physis, of which three (60%) had tumors confined solely to the metaphysis. Of the five patients with open physis, four (80%) developed local recurrence while only one patient (11%) with a closed physis had local recurrence (p value = 0.0023). Our results illustrate that for the skeletally immature, GCT can (and in our results more commonly did) occur in the metaphyseal location. These findings suggest that GCT should be included in the differential diagnosis of primary metaphyseal-only lesions in the skeletally immature.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Investigation of Giant Cell Tumor of Bone and Tissue Engineering Approaches for the Treatment of Giant Cell Tumor of Bone

Primary bone tumors such as Ewing sarcoma, osteosarcoma, and chondrosarcoma, secondary bone tumors developed from progressive malignancies, and metastasized bone tumors are more prevalent and studied descriptively through biology and medical research. Less than 0.2% of cancer diagnoses are caused by rare bone-originating tumors, which despite being rare are particularly difficult due to their high death rates and substantial disease burden. A giant cell tumor of bone (GCTB) is an intramurally invasive but rare and benign type of bone tumor, which seldom metastasizes. The most often prescribed medication for GCTB is Denosumab, a RANKL (receptor activator of nuclear factor κB ligand) inhibitor. Because pharmaceutical drug companies rely on two-dimensional and animal models, current approaches for investigating the diverse nature of tumors are insufficient. Cell line based medication effectiveness and toxicity studies cannot predict tumor response to antitumor medicines. It has already been investigated in detail why molecular pathways do not reproduce in vitro, a phenomenon known as flat biology. Due to physiological differences between human beings and animals, animal models do not succeed in identifying side effects of the treatment, emulating metastatic growth, and establishing the link between cancer and the immune system. This review summarizes and discusses GCTB, the disease, its cellular composition, various bone tumor models, and their properties and utilization in research. As a result, this study delves deep into in vitro testing, which is vital for scientists and physicians in various fields, including pharmacology, preclinical investigations, tissue engineering, and regenerative medicine.

Giant Cell Tumour of Bone: A Comprehensive Review of Pathogenesis, Diagnosis, and Treatment

The benign aggressive tumour known as a giant cell tumour of bone (GCTB) frequently affects the knee bones. Patients suffering from GCTB present with pain, swelling, joint effusion, loss of ability to bear weight on the involved extremity and a restriction in the range of motion of the afflicted joint may also exist, depending on the tumour's size. GCTB makes up 20% of benign skeletal tumours and 5% of all primary bone tumours. Although it has an equal distribution of the sexes, the majority reveal a higher frequency among women. Eighty per cent of GCTB instances were recorded in patients between the ages of 20 and 50 during the third decade. The femur, tibia and radius are where GCTB is most frequently discovered. Lesions can be rated using the Campanacci grading method based on the plain radiograph's results. Plain radiography, CT and MRI are used to diagnose the tumour. Surgery is the only curative treatment which is determined by the Campanacci grade and the tumour's location. Recurrence of GCTB is observed in about 25% of patients, with curettage being associated with rates as high as 50%. We evaluated the GCTB-related articles and summarised the developments in diagnosis, treatment and reducing risk of recurrence.

Maxillary Sinusitis Induced by Medication-Related Osteonecrosis of the Jaw

The involvement of maxillary sinuses in patients taking bone-related medications has not been comprehensively considered in the literature, mostly dental. Considering the fact that paranasal sinuses are often captured in dental radiographs, it is incumbent upon dental practitioners to recognize abnormal presentations in the paranasal sinuses to ensure the appropriate management of medication-related osteonecrosis of the jaw (MRONJ). We present a case of a giant cell tumor (GCT) with atypical chronic sinusitis manifestation leading to MRONJ.

Establishment and characterization of two novel patient-derived cell lines from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare bone tumor with osteolytic features, composed of stromal cells with a monotonous appearance, macrophages, and osteoclast-like giant cells. GCTB is commonly associated with a pathogenic mutation in the H3-3A gene. While complete surgical resection is the standard cure for GCTB, it often results in local recurrence and, rarely, metastasis. Thus, an effective multidisciplinary treatment approach is necessary. Although patient-derived cell lines is an essential tool for investigating novel treatment strategies, there are only four GCTB cell lines available in public cell banks. Therefore, this study aimed to establish novel GCTB cell lines and successfully created NCC-GCTB6-C1 and NCC-GCTB7-C1 cell lines from two patients' surgically removed tumor tissues. These cell lines exhibited H3-3A gene mutations, consistent proliferation, and invasive properties. After characterizing their behaviors, we performed high-throughput screening of 214 anti-cancer drugs for NCC-GCTB6-C1 and NCC-GCTB7-C1 and integrated their screening data with those of NCC-GCTB1-C1, NCC-GCTB2-C1, NCC-GCTB3-C1, NCC-GCTB4-C1, and NCC-GCTB5-C1 that we previously established. We identified histone deacetylase inhibitor romidepsin as a possible treatment for GCTB. These findings suggest that NCC-GCTB6-C1 and NCC-GCTB7-C1 could be valuable tools for preclinical and basic research on GCTB.

Reconstruction After En Bloc Resection of a Distal Radius Tumor. An Updated and Concise Review

The distal radius is rarely affected by either primary or metastatic bone cancers. The most frequent tumors of the distal radius are giant cell tumors, which are benign tumors with the propensity to invade. En bloc excision of giant cell tumors of the distal radius achieves a low recurrence rate but compromises the wrist joint, necessitates a significant reconstruction, and has functional consequences. Reconstruction after en bloc resection of a distal radius bone tumor is challenging. Furthermore, orthopedic oncologists disagree on treating such long bone anomalies most effectively. The present article summarizes the various biological and non-biological reconstruction techniques performed after en bloc resection of a distal radius tumor, discusses the advantages and disadvantages of each reconstruction strategy, and summarizes several case studies and case reports.

The Rare Occurrence of Giant Cell Tumor of the Proximal Tibia With Pathological Fracture in an Elderly Male: A Case Report

Giant cell tumor of the bone (GCTB) is a benign bone tumor that can occasionally progress to malignancy, usually in chronic cases. It is a common benign and aggressive bone tumor that affects patients aged between 20 and 45 years. The most common location is the knee joint. It manifests as a painless or occasionally painful swelling over the affected area. A case of giant cell tumor (GCT) of the proximal tibia in a 72-year-old male is reported here, which was difficult to diagnose as it is rarely found in the geriatric age group. The patient came with a chief complaint of pain and swelling over his left knee for two months with a history of trauma to the knee a couple of times. On clinical examination, the patient had grade 3 tenderness and swelling on the anterolateral aspect of the knee extending toward the proximal tibia. The swelling was well-defined, smooth, firm, and uniform in consistency with dimensions of 15 cm × 12 cm. The swelling was moveable sideways, and the movement of the knee suggested that it was not attached to the underlying bone. As per the age and history of the rapid-growing lesion, we suspected malignancy, but clinical findings were pointing toward benign tumor. X-ray of the affected knee was done, which revealed a soft tissue mass with the involvement of the bone. Magnetic resonance imaging (MRI) of the knee revealed a soft tissue mass with the cortical breach. An open biopsy was done for the confirmation of the diagnosis, which was later reported and confirmed as a giant cell tumor of the proximal tibia. As bone tumor is associated with a cortical breach and pathological fracture, it was classified under Campanacci grade 3, for which an en bloc resection and open reduction and internal fixation with plate osteosynthesis with bone cementing and bone grafting were done followed by knee bending physiotherapy and gradual weight-bearing. Finally, the knee function was improved with pain relief.

Management of giant cell tumors of the distal radius

Background

The distal radius is the most common location for giant cell tumors (GCT) in the upper extremity. Treatment should balance the goals of maximizing function and minimizing recurrence and other complications. Given the complexity in surgical treatment, various techniques have been described without clear standards of treatment.

Objectives

The purpose of this review is to provide an overview of evaluation of patients presenting with GCT of the distal radius, discuss management, and provide an updated summary on outcomes of treatment options.

Conclusion

Surgical treatment should consider tumor Grade, involvement of the articular surface, and patient-specific factors. Options include intralesional curettage and en bloc resection with reconstruction. Within reconstruction techniques, radiocarpal joint preserving and sparing procedures can be considered. Campanacci Grade 1 tumors can be successfully treated with joint preserving procedures, whereas for Campanacci Grade 3 tumors consideration should be given to joint resection to prevent recurrence. Treatment of Campanacci Grade 2 tumors is debated in the literature. Intralesional curettage and adjuvants can successfully treat cases where the articular surface can be preserved, while en-bloc resection should be used in cases where the articular surface cannot undergo aggressive curettage. A variety of reconstructive techniques are used for cases needing resection, with no clear gold standard. Joint sparing procedures preserve motion at the wrist joint, whereas joint sacrificing procedures preserve grip strength. Choice of reconstructive procedure should be made based on patient-specific factors, considering relative functional outcomes, complications, and recurrence rates.

A systematic review of radiomics in giant cell tumor of bone (GCTB): the potential of analysis on individual radiomics feature for identifying genuine promising imaging biomarkers

PURPOSE

To systematically assess the quality of radiomics research in giant cell tumor of bone (GCTB) and to test the feasibility of analysis at the level of radiomics feature.

METHODS

We searched PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang Data to identify articles of GCTB radiomics until 31 July 2022. The studies were assessed by radiomics quality score (RQS), transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) statement, checklist for artificial intelligence in medical imaging (CLAIM), and modified quality assessment of diagnostic accuracy studies (QUADAS-2) tool. The radiomic features selected for model development were documented.

RESULTS

Nine articles were included. The average of the ideal percentage of RQS, the TRIPOD adherence rate and the CLAIM adherence rate were 26%, 56%, and 57%, respectively. The risk of bias and applicability concerns were mainly related to the index test. The shortness in external validation and open science were repeatedly emphasized. In GCTB radiomics models, the gray level co-occurrence matrix features (40%), first order features (28%), and gray-level run-length matrix features (18%) were most selected features out of all reported features. However, none of the individual feature has appeared repeatably in multiple studies. It is not possible to meta-analyze radiomics features at present.

CONCLUSION

The quality of GCTB radiomics studies is suboptimal. The reporting of individual radiomics feature data is encouraged. The analysis at the level of radiomics feature has potential to generate more practicable evidence for translating radiomics into clinical application.

Bilateral Simultaneous Primary Patellar Giant Cell Tumors

Giant cell tumor is a relatively frequent benign bone tumor; that is usually exhibited in the epiphyseo-metaphyseal region of long bones. Computed tomography and magnetic resonance imaging may show cortical thinning and endosteal scalloping of the bone cortex in giant cell tumors. In radiologic imaging, the giant cell tumor of the bone is a heterogeneous mass because it contains many components, such as solitary mass, cystic areas, and bleeding. The occurrence of giant cell bone tumor in the patella is a rare condition and in this letter, we have reported the unusual coexistence of giant cell tumor on the bilateral patella at the same time. To the best of our knowledge, there is no reported case in the literature of bilateral patellar giant cell tumors.

The optimal strategy for 3D-printed uncemented endoprosthesis for the bone defect reconstruction of the distal radius, based on biomechanical analysis and retrospective cohort study

INTRODUCTION

Prosthetic reconstruction after resecting giant cell tumor of bone (GCTB) of the distal radius has been proposed. However, this is generally associated with various complications. To improve the functional outcomes, we designed a three-dimensional (3D)-printed uncemented endoprosthesis. Meanwhile, using finite-element analysis and clinical observation, an optimization strategy was explored.

MATERIALS AND METHODS

We retrospectively analyzed patients with Campanacci III or recurrent GCTB of the distal radius who underwent 3D-printed uncemented endoprosthesis reconstruction. Clinically, according to the different palmar tilts of the endoprosthesis, patients were divided into the biological angle (BA) group and the zero-degree (ZD) group. We recorded and evaluated the differences in functional outcomes and complications between the two groups. Biomechanically, four 3D finite-element models (normal and customized endoprostheses with three different implemented palmar tilts) were developed.

RESULTS

We analyzed 22 patients (12 males and 10 females). The median follow-up period was 60 (range, 19-82) months. Of the 22 patients, 11 patients were included in the BA group and the remaining 11 patients were in the ZD group. Both groups showed no significant differences in the range of motion, Mayo score, and disabilities of the arm, shoulder, and hand scores postoperatively. The subluxation rate was significantly lower in the ZD group than in the BA group. The biomechanical results showed similar stress and displacement distribution patterns in the normal and prosthetic reconstruction models. Additionally, the endoprosthesis with 0° palmar tilt showed better biomechanical performance.

CONCLUSION

3D-printed uncemented endoprosthesis provides acceptable midterm outcomes in patients undergoing distal radius reconstruction. Optimizing the design by decreasing the palmar tilt may be beneficial for decreasing the risk of wrist joint subluxation.

Denosumab salvage therapy in an 11-year-old boy with locally recurrent unresectable giant cell tumor of the lumbar spine after surgery

Giant cell tumors (GCTs) of the bone are locally aggressive primary bone tumors with a benign character. Spinal involvement is rare which accounts for approximately 5% of all primary bone tumors and it is quite rare in the lumbar spine. An 11-year-old boy patient presented with pain of low back and bilateral low extremities. Lumbar CT and MRI revealed a lytic lesion of the L4 vertebra corpus. The patient earned remarkable and timely recovery with 2 surgical interventions and the use of denosumab. Surgical resection for GCTs is still preferable as the initial treatment, denosumab should be utilized after tumor resection whether based on the purpose of prevention or treatment of tumor recurrence.

CT-Guided RFA for Management of Surgical Relapses of Giant Cell Tumour of Bone

OBJECTIVES

This retrospective study describes a pilot experience in CT-guided RadioFrequency Ablation (RFA) treatment of 5 Giant Cell Tumour of the bone (GCT) recurrences after surgery.

METHODS

After biopsy to confirm the diagnosis of GCT recurrences, all patients were treated with RFA in a single session. A close follow-up was scheduled with contrast-enhanced MRI starting 1 months after treatment.

RESULTS

Five lesions were treated in 5 patients. The length of the observation period was between 4 and 100 months. One lesion relapsed 4 months after the RFA treatment, and the patient underwent a second surgical treatment which included the en-block resection and prosthetic implant. No complications were recorded.

CONCLUSIONS

The management of GCT relapses with RFA could be an interesting and innovative field. However, the results of this limited series need to be confirmed by further investigations of larger patient cohorts.

Talar metastasis of mucinous lung adenocarcinoma with fluid-fluid levels: a rare presentation mimicking a benign tumor

The differential diagnosis of bone tumors in the talus is broad and includes both benign and malignant conditions. Metastases, although very rare, are one of these conditions. The typical nonspecific clinical and radiological presentations of metastases are a diagnostic challenge, and a high level of suspicion is needed in order to perform an adequate diagnostic approach. Moreover, they can present with features which have classically been associated with benign conditions such as fluid-fluid levels. We present a rare case of talar metastasis of a mucinous pulmonary adenocarcinoma that presented with fluid-fluid levels and was initially misdiagnosed as a giant-cell tumor with areas of secondary aneurysmal bone cyst transformation.

Additively manufactured Bi-functionalized bioceramics for reconstruction of bone tumor defects

Bone tissue exhibits critical factors for metastatic cancer cells and represents an extremely pleasant spot for further growth of tumors. The number of metastatic bone lesions and primary tumors that arise directly from cells comprised in the bone milieu is constantly increasing. Bioceramics have recently received significant attention in bone tissue engineering and local drug delivery applications. Additionally, additive manufacturing of bioceramics offers unprecedented advantages including the possibilities to fill irregular voids after the resection and fabricate patient-specific implants. Herein, we investigated the recent advances in additively manufactured bioceramics and ceramic-based composites that were used in the local bone tumor treatment and reconstruction of bone tumor defects. Furthermore, it has been extensively explained how to bi-functionalize ceramics-based biomaterials and what current limitations impede their clinical application. We have also discussed the importance of further development into ceramic-based biomaterials and molecular biology of bone tumors to: (1) discover new potential therapeutic targets to enhance conventional therapies, (2) local delivering of bio-molecular agents in a customized and "smart" way, and (3) accomplish a complete elimination of tumor cells in order to prevent tumor recurrence formation. We emphasized that by developing the research focus on the introduction of novel 3D-printed bioceramics with unique properties such as stimuli responsiveness, it will be possible to fabricate smart bioceramics that promote bone regeneration while minimizing the side-effects and effectively eradicate bone tumors while promoting bone regeneration. In fact, by combining all these therapeutic strategies and additive manufacturing, it is likely to provide personalized tumor-targeting therapies for cancer patients in the foreseeable future. STATEMENT OF SIGNIFICANCE: To increase the survival rates of cancer patients, different strategies such as surgery, reconstruction, chemotherapy, radiotherapy, etc have proven to be essential. Nonetheless, these therapeutic protocols have reached a plateau in their effectiveness due to limitations including drug resistance, tumor recurrence after surgery, toxic side-effects, and impaired bone regeneration following tumor resection. Hence, novel approaches to specifically and locally attack cancer cells, while also regenerating the damaged bony tissue, have being developed in the past years. This review sheds light to the novel approaches that enhance local bone tumor therapy and reconstruction procedures by combining additive manufacturing of ceramic biomaterials and other polymers, bioactive molecules, nanoparticles to affect bone tumor functions, metabolism, and microenvironment.

Giant Cell Tumor of the Wrist After Fracture Osteosynthesis: A Case Report

A 60-year-old female sustained a distal radius fracture and underwent open reduction internal fixation with a volar locking plate. The patient had an uneventful recovery until four months postoperatively when the patient clinically regressed, and an expansile, radiolucent metaepiphyseal lesion was found. Further workup revealed this was a giant cell tumor of bone (GCTB). Definitive management consisted of extensive curettage, cryoablation, and cementation of the lesion, and the hardware was left intact. The current case presents an uncommon presentation of GCTB. The case illuminates the importance of thorough scrutiny of postoperative radiographs when clinical improvement plateaus or regresses and the need to pursue additional workup when the clinical course is atypical. The authors query the possibility of a sub-radiological presentation of GCTB.

A Retrospective Observational Study on Disease Characteristics and Treatment Patterns of Giant Cell Tumor of the Bone in China

Aims

Giant cell tumor of the bone (GCTB) is associated with considerable morbidity. As GCTB epidemiological data for China are limited, this study is aimed at describing the disease characteristics of GCTB in China and establishing the historical context for its treatment before recent advances in treatment options.

Methods

The disease characteristics, treatment patterns, and local GCTB recurrence rate after primary surgery for GCTB were evaluated in this single-center, retrospective, noninterventional, observational study of patients treated for GCTB at Ji Shui Tan Hospital, Beijing, from 2009 to 2016 based on medical chart review. Patients with unmet need were defined as those whose surgical treatment was difficult or who had to undergo high-morbidity surgery.

Results

Among the 668 patients with a primary GCTB diagnosis, 578 (86.5%) of target lesions were in the extremities, and 89 (13.3%) were in the pelvic or axial bone. Of these, 173 (25.9%) were characterized as having an unmet need. Almost all GCTB patients received surgical treatment at both primary diagnosis (666/668 (99.7%)) and last disease recurrence (196/200 (98.0%)). Additionally, about one-third of patients received nonsurgical treatment at primary diagnosis (205/668 (30.7%)) and disease recurrence (67/200 (33.5%)), with neoadjuvant therapy being the most common treatment. The rate of high-morbidity surgery increased for recurrent disease (65/200 (32.5%)) compared with primary diagnosis (111/668 (16.6%)). The 2-year cumulative incidence of postoperative disease recurrence was 29.2%, in line with rates observed in prior studies.

Conclusion

As many patients with primary and recurrent disease received high-morbidity surgery, more effective treatments are needed.

Giant Cell Tumor of Lumbar Vertebrae on MR and 18F- FDG PET/CT: A Case Report and Literature Review

Teaching Point: Giant cell tumor of bone may show a moderate to high FDG uptake, and attention should be paid to differentiate from malignant tumors.

Giant Cell Tumor of the Distal Radius: A Review

Giant cell tumor of the distal radius presents a significant challenge in management due to high risk of recurrence and potential loss of function. Shared decision-making guides management, particularly for more advanced lesions. Intralesional curettage can optimize wrist function but at the cost of a higher recurrence risk. Wide resection decreases local recurrence but has higher complication rates regardless of reconstruction method. No functional difference exists between motion-preserving procedures and arthrodesis; therefore, patients should be clearly informed of the risks and benefits of each treatment option.