Giant cell tumor of bone: Unusual features of a rare tumor

Role of H3F3A (H3G34W) antibody in the diagnosis of giant cell tumour of bone in the paediatric age group

Giant cell tumour of the bone (GCTB) occurring in paediatric patients is rare and may presents with atypical histology. Given that giant cell tumour mimics, such as osteosarcoma, are more prevalent in this demographic, diagnosing GCTB can often be challenging. This study aimed to investigate the efficacy of H3F3A immunohistochemistry (IHC) in the diagnosis of GCTB in the immature skeleton. This retrospective study included paediatric patients who were diagnosed with GCTB between 2009 and 2024. Histological features were re-evaluated and IHC staining was performed. Giant cell tumour mimics were included in the control group. 72 biopsy proven GCTB were reported in the paediatric patients during the study period. The age ranged from 12 to 18 years, with a median age of 16 ( ± 1.8) years. 49 (68.1 %) were females and 23 (31.9 %) were males (female to male ratio of 2.1:1). Tibia was most common site (23) involved followed by femur (12), fibula (8) and small bones of hand and feet (8). H3G34W was positive in 61 (84.7 %) of GCTB cases (p < 0.01); and negative in all 33 GCTB mimics. H3G34V was positive in 3 of 11 H3G34W negative cases. All these 11 cases were negative for H3G34R and keratin AE1/AE3. Significant association of GCTB was found with gender (p = 0.02) and site of the tumour (p < 0.01). HG34W was not associated with tumour site (p = 0.4533) or biopsy yield (p = 0.4533). A sensitivity of 84.74 %, specificity of 100 %, positive predictive value of 75 % and negative predictive value of 100 % was established. An ROC was constructed, with area under the curve of 0.924 (95 % CI 0.88-0.97). In conclusion H3G34W antibody is a valuable diagnostic tool for accurately diagnosing GCTB and distinguishing it from other giant cell mimics. Additionally, since a minimal tissue yield is adequate for determining the diagnosis, the need for larger biopsies is reduced.

Molecular pathological insights into tumorigenesis and progression of giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a primary bone tumor that typically exhibits benign histological appearance and clinical behavior in most cases, with local aggressiveness and rare metastasis. It predominantly affects individuals in the young adult age group. It is characterized by the presence of multinucleated osteoclastic giant cells and a stromal population of neoplastic cells. A key hallmark for GCTB pathogenesis is the G34W genetic mutation in the histone H3.3 gene, which is restricted to the population of cancerous stromal cells and is absent in osteoclasts and their progenitor cells. This review presents a comprehensive overview of the pathology of GCTB, including its histopathological characteristics, cytological features, histopathological variants, and their clinical relevance. We also discuss recent insights into genetic alterations in relation to the molecular pathways implicated in GCTB. A summary of the current understanding of GCTB pathology will update the knowledge base to guide the diagnosis and management of this unique bone tumor.

Rare features of giant cell tumors of the bone: A case report

Giant cell tumors of the bone are local invasive diseases that are mainly composed of neoplastic monocytes and nonneoplastic multinucleated giant cells, mostly in the long bones of patients with mature bones. A specific H3F3A mutation is the key to its diagnosis. The present paper reports a case of giant cell tumor of the bone (GCTB) characterized by diffuse cholesterol crystals with few multinucleated giant cells. Imaging examination combined with immunohistochemical H3.3 G34W positivity was used to diagnose the patient with GCTB. Understanding the unique histological morphology of this patient will help doctors correctly diagnose giant cell tumors of bone and avoid misdiagnosis.

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.

Excision of a Giant Cell Tumor With Bone Grafting and Bone Cementing of the Proximal Humerus: A Case Report

Giant cell tumors (GCTs) of the bone are uncommon neoplasms that predominantly affect the metaphysis of long bones, with proximal humerus involvement being less frequent. We present the case of a 58-year-old male who presented with a two-month history of progressive right shoulder pain and difficulty in raising his arm. Clinical examination revealed a palpable swelling on the lateral aspect of the right arm. Radiological investigations, including X-ray and magnetic resonance imaging (MRI), confirmed the presence of a primary osseous neoplasm involving the proximal humerus, suggestive of a GCT. The patient underwent surgical excision of the tumor with bone grafting and bone cementing of the proximal humerus. Post-operative care included prescribed medications and physiotherapy. This case highlights the successful management of GCTs of the proximal humerus through a multidisciplinary approach, emphasizing the importance of meticulous surgical technique, appropriate reconstruction, and comprehensive post-operative care for optimal patient outcomes.

Multicentric Giant Cell Tumor of Bone

The typical presentation of giant cell tumor of bone is a solitary lesion involving the meta-epiphyseal region of the long bones. The presence of more than one distinct giant cell tumor in the same patient is rare. This study reports on 7 patients with multicentric giant cell tumor of bone. Clinical and radiologic features were reviewed to evaluate the behavior of multicentric giant cell tumor of bone. Immunohistochemistry and genetic analysis for the H3F3A gene were performed to confirm the diagnosis. The knee was most frequently involved, and most of the lesions were in an ipsilateral extremity. All of the patients received surgical management with curettage or resection. The overall median follow-up was 194 months (interquartile range, 41-336 months). Five of 7 patients had local recurrence (71%), but considering the number of surgically treated lesions, the risk of local recurrence was 33% (5 local recurrences among 15 treated lesions). No lung metastases occurred. Multicentric giant cell tumor of bone tends to exhibit the same aggressive clinical behavior as solitary giant cell tumor of bone. Patients should be monitored for the occurrence of other lesions, especially in the ipsilateral extremity. [Orthopedics. 2023;46(6):e376-e380.].

Effect of Local Adjuvants Following Curettage of Benign and Intermediate Tumours of Bone: A Systematic Review of the Literature

Local adjuvants are used upon intralesional resection of benign/intermediate bone tumours, aiming at reducing the local recurrence (LR) rate. However, it is under debate whether, when and which local adjuvants should be used. This PRISMA-guideline based systematic review aimed to analyse studies reporting on the role of adjuvants in benign/intermediate bone tumours. All original articles published between January 1995 and April 2020 were potentially eligible. Of 344 studies identified, 58 met the final inclusion criteria and were further analysed. Articles were screened for adjuvant and tumour type, follow-up period, surgical treatment, and development of LR. Differences in LR rates were analysed using chi-squared tests. Altogether, 3316 cases (10 different tumour entities) were analysed. Overall, 32 different therapeutic approaches were identified. The most common were curettage combined with high-speed burr (n = 774; 23.3%) and high-speed burr only (n = 620; 18.7%). The LR rate for studies with a minimum follow-up of 24 months (n = 30; 51.7%) was 12.5% (185/1483), with the highest rate found in GCT (16.7%; 144/861). In comparison to a combination of curettage, any adjuvant and PMMA, the sole application of curettage and high-speed burr (p = 0.015) reduced the LR rate in GCT. The overall complication rate was 9.6% (263/2732), which was most commonly attributable to postoperative fracture (n = 68) and osteoarthritis of an adjacent joint during follow-up (n = 62). A variety of adjuvants treatment options are reported in the literature. However, the most important step remains to be thorough curettage, ideally combined with high-speed burring.

Giant Cell Tumor of the Distal Fibula Managed by an Autologous Proximal Fibula Graft

A giant cell tumor of the bone is among the most common bone tumors encountered by orthopedic surgeons. These benign and aggressive tumors are most commonly present around the knee joint; however, rare cases may involve the distal fibula. An 18-year-old man presented with a painless swelling of the lateral aspect of the left ankle. Clinical examination, radiologic evaluation, and biopsy confirmed the diagnosis of a giant cell tumor of the distal fibula. The patient was treated with resection of the distal fibula followed by reconstruction using an ipsilateral proximal fibula graft. The post-operative recovery was uneventful, and the patient was doing well on the last visit, one month after the intervention.

MiR-217 regulates autophagy through OPG/RANKL/RANK in giant cell tumors

BACKGROUND

Increasing evidence suggests that microRNAs (miRNAs) play a crucial role in cancer development and progression. Our previous study showed remarkably lower levels of miR-217 in GCT cells and tissues, and miR-217 re-expression inhibited the occurrence and development of GCT in vitro; however, the associated mechanisms remain unknown. Thus, this study aimed to explore the mechanisms underlying the proliferation inhibitory effect of miR-217 in GCT cells.

METHODS

The proliferative potential of the GCT cells was measured with an MTT assay and BrdU straining. Changes in GCT cell migration and invasion was assessed by a transwell assay. Finally, Western blot and RT-PCR assays were employed to evaluate OPG/RANKL/RANK signaling pathway-related protein expression.

RESULTS

The excessive upregulation of miR-217 markedly suppressed GCT cell proliferation and tumorigenesis both in vitro and in vivo. miR-217 overexpression could inhibit the OPG/RANKL/RANK signaling pathway in vitro and in vivo. Furthermore, ALP activity was significantly decreased in GCT cells following miR-217 treatment. Importantly, miR-217 could inhibit autophagy-related protein expression and autophagosome/autolysosome formation in GCT cells and tissues.

CONCLUSION

These results suggest that miR-217 upregulation could inhibit the occurrence and development of GCT by blocking autophagy. These findings offer an effective therapeutic target to improve the survival rates of patients with CGT in the future.

Diagnostic value of H3F3A mutation and clinicopathological features of giant cell tumours in non-long bones

Aims

A histone H3F3A (H3.3) mutation involving a substitution in H3.3 G34 recently has been reported in GCTB within the frequency range (from 69 % to 96 %) and is a helpful diagnostic indicator of GCTB. However, the relationship between H3F3A mutations and the clinicopathological feature of GCTB involving non-long bones (irregular bones and small bones) is unclear.

Methods and results

H3F3A mutations were observed in a cohort of specimens (230 samples of GCTB) using immunohistochemistry and Sanger sequencing. The relationship between H3F3A mutations and the clinicopathological characteristics of patients with GCTB occurring in the non-long bones of the appendicular skeleton was investigated. No significant difference between H3F3A mutations in GCTB arising in non-long bones and the classic sites was found (P = 0.483). GCTB in non-long bones occurred more common in female (31/49, 63.3 %) than in male patients (P = 0.016). GCTB with H3.3 G34L/V/R mutation occurred more often in younger patients compared with those with H3.3 G34W mutation (P = 0.009). The majority of GCTB with soft tissue extension developed in irregular bones but not in small bones (P = 0.061). The H3.3 G34L/V/R mutations rate (7/45) in the non-long bones was significantly higher than that in long bones. The recurrence rate of the GCTB in long bones and non-long bones was 23.3 % (45/193) including 43 cases with local recurrene and 2 cases with lung metastasis. No recurrence occurred in cases with G34V/L/R mutations.

Conclusions

H3F3A was an effective diagnostic marker for GCTB of the non-long bones. The younger patients with GCTB of the non-long bones harboured H3.3 G34L/V/R mutations and may had a female preference and rarely recurrent.

Siglec-15 as a New Perspective Therapy Target in Human Giant Cell Tumor of Bone

The main features of a giant cell tumor of bone (GCTB) are frequent recurrence and aggressive osteolysis, which leads to a poor prognosis in patients. Although the treatment methods for a GCTB, such as scraping and resection, effectively inhibit the disease, the tendency toward malignant transformation remains. Therefore, it is important to identify new treatment methods for a GCTB. In this study, we first found high Siglec-15 expression in GCTB tissues, which was significantly associated with Campanacci staging and tumor recurrence. In Spearman's analysis, Siglec-15 expression was significantly correlated with Ki-67 levels in tumor tissues. In vitro, the mRNA and protein levels of Siglec-15 were high in GCTB stromal cells (Hs737. T), and Siglec-15 knockdown inhibited the biological characteristics of GCTB stromal cells. The RNA sequencing results enabled a prediction of the downstream genes by using the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and MCODE analyses, and the findings showed that CXCL8 was significantly regulated by Siglec-15 and might be a promising downstream target gene of Siglec-15. Therefore, Siglec-15 may be a potential immunotherapy target for a GCTB.

Secondary Malignancy in Giant Cell Tumor: A Single-Center Study

Giant cell tumor of bone (GCTB) undergoes a sarcomatous transformation. Secondary malignancy in giant cell tumor (MGCT) is associated with radiotherapy and has a dismal prognosis. We reviewed medical records to investigate the clinicopathological characteristics and prognosis of MGCT patients. The enrollment criterion was high-grade spindle-cell sarcoma, which developed at the site of prior GCTB treatment. Twelve patients were analyzed: six females and six males. The median age was 42.5 years. Benign recurrence occurred in five GCTB patients not treated with radiotherapy. No pulmonary implants were observed. The median latency to the malignant transformation was 63 months. Nine patients were AJCC stage IIB, and three were stage IVA. The median follow-up period after malignant transformation was 62.5 months. Five patients developed local recurrence, and six had distant metastasis. Five-year overall recurrence and metastasis-free survival rates were 61.9%, 66.7%, and 58.3%, respectively. Initial metastasis was a predictive factor for overall survival. Benign local recurrence of GCTB was also a negative factor for metastasis-free survival of MGCT patients. Differences in overall survival according to benign recurrence also showed a tendency toward significance. In our series, secondary MGCT did not occur after radiotherapy. The prognosis was better than previous findings. Benign recurrence of GCTB could reflect the prognosis of MGCT.

3D-printed personalised prostheses for bone defect repair and reconstruction following resection of metacarpal giant cell tumours

Background

Conventional surgical treatment for metacarpal giant cell tumours (GCTs) includes lesion scraping followed by bone grafting or bone cement filling and en bloc resection followed by repair and reconstruction using a vascularised bone flap. However, these methods have inherent shortcomings, including a high postoperative recurrence rate and poor mechanical stability. 3D-printing techniques are increasingly being applied in medicine, and 3D-printed personalised prostheses have achieved good clinical effects in orthopaedic repair and reconstruction. We aimed to investigate the clinical effects of 3D-printed personalised prostheses for bone defect repair and reconstruction following resection of metacarpal GCTs.

Methods

Three patients with metacarpal GCTs were examined in a retrospective cohort study. Through preoperative planning, a 3D-printed personalised prosthesis was designed and created for bone defect repair and reconstruction after tumour resection. Prosthesis fit, limb function, pain on the affected side, and the occurrence of complications were evaluated postoperatively.

Results

Postoperative X-ray examination revealed a satisfactory fit of the 3D-printed prosthesis in terms of bone defect size and overall metacarpal shape, as well as good transverse and longitudinal metacarpal arches. The patients also exhibited good function in the affected limb, with good flexion and extension functions in the carpal, metacarpophalangeal, and interphalangeal joints, plus the absence of obvious pain, tumour recurrence, and complications such as pathologic fractures and prosthetic loosening.

Conclusions

When using a 3D-printed personalised prosthesis for bone defect repair and reconstruction following resection of metacarpal GCTs, a good fit with the bone defect can be achieved during prosthetic installation when preoperative planning and design have been adequately performed. Therefore, three-dimensionally printed personalised prostheses can serve as an effective method for the treatment of metacarpal GCTs.

Vascularized Ulnar Transposition and Radioulnoscapholunate Fusion With Volar Locking Plate in a Dorsal Position Following Resection of Giant Cell Tumor of the Distal Radius

Giant cell tumor of the distal radius is a rare, locally destructive, and frequently recurrent tumor. We present a case of Campanacci Grade III giant cell tumor of the distal radius with pathologic fracture and cortical destruction which was treated with neoadjuvant denosumab. This facilitated en-bloc resection of the entire distal radius, including the articular surface, while minimizing tumor contamination. Reconstruction was accomplished using a vascularized ulnar transposition flap to facilitate radioulnoscapholunate fusion, which was fixated using a long-stem contralateral variable angle locking volar distal radius plate in a dorsal position. This case illustrates multidisciplinary management of a challenging reconstructive problem and demonstrates a novel strategy for fixation which repurposes familiar and readily available hardware to provide optimal osteosynthesis.

Giant cell tumor of the sacrum

Giant cell tumor of the sacrum is a rare primary tumor in a challenging anatomical location without clear consensus on treatment. We present a case of giant cell tumor of the sacrum and subsequent treatment with preoperative embolization, L5 to S4 laminectomy, partial sacrectomy, intraoperative thermal ablation, and L4 to pelvis stabilization and fusion.