Clinicopathologic and prognostic characteristics of tumor budding-like in giant cell tumor of bone.

BACKGROUND: Currently, tumor budding (TB) is defined as an important factor for a poor prognosis in various types of cancers. The authors identified a significant presence of TB-like structures at the tumor invasive front in giant cell tumor of bone (GCTB), which may have the same biologic function as TB. The objective of this report was to describe the distribution of TB in GCTB and investigate its correlation with clinicopathologic characteristics, the immune microenvironment, survival prognosis, and response to denosumab treatment. METHODS: This multicenter cohort study included 426 patients with GCTB who received treatment between 2012 and 2021 at four centers. Two independent pathologists performed visual assessments of TBL structures in hematoxylin-and-eosin-stained tumor sections. Immunohistochemistry was used to evaluate tumor-infiltrating lymphocyte subtypes (CD3-positive, CD4-positive, CD8-positive, CD20-positive, programmed cell death protein-1-positive, programmed cell death-ligand 1positive, and FoxP3-positive) as well as Ki-67 expression levels in 426 tissue samples. These parameters were then analyzed for associations with patient outcomes (local recurrence-free survival [LRFS] and overall survival [OS]), clinicopathologic characteristics, and response to denosumab treatment. RESULTS: High-grade TB was associated with poorer LRFS and OS in both patient groups. In addition, TB was correlated with various clinicopathologic features, tumor-infiltrating lymphocyte expression, and response to denosumab treatment. TB outperformed the traditional Enneking and Campanacci staging systems in predicting patient LRFS and OS. CONCLUSIONS: The current data support the assessment of TBL structures as a reliable prognostic tool in GCTB, potentially aiding in the development of personalized treatment strategies for patients.

Real-World Patient Experience of Pexidartinib for Tenosynovial Giant-Cell Tumor.

BACKGROUND: Pexidartinib (Turalio) is the only systemic therapy approved by the FDA for the treatment of adult patients with symptomatic tenosynovial giant-cell tumor (TGCT) associated with severe morbidity or functional limitations, and not amenable to improvement with surgery. This study assessed patient-reported treatment experiences and symptom improvement among patients receiving pexidartinib. METHODS: A cross-sectional, web-based survey collected data on demographics, disease history, pexidartinib dosing, and symptoms before and after pexidartinib use. RESULTS: Of 288 patients enrolled in the Turalio REMS program in May 2021, 83 completed the survey: mean age was 44.2 years, 62.7% were female, and most common tumor sites were in knee (61%) and ankle (12%). Mean initial dose was 622 mg/day: 29 patients reported reduction from initial dose and 8 had dose reduction after titrating up to a higher dose. At the time of survey completion, median time on pexidartinib was 6.0 months; 22 (26.5%) patients discontinued pexidartinib due to physician suggestion, abnormal laboratory results, side effect, or symptom improvement. Compared with before pexidartinib initiation, most patients reported improvement in overall TGCT symptom (78.3%) and physical function (77.2%) during pexidartinib treatment. Significant improvement was reported during pexidartinib treatment in worst stiffness numeric rating scale (NRS) (3.0 vs. 6.2, P < .05) and worst pain NRS (2.7 vs. 5.7, P < .05). CONCLUSION: Findings from this cross-sectional survey confirmed the benefit of pexidartinib in improving symptoms and functional outcomes among patients with symptomatic TGCTs from the patients' perspective. Future research is warranted to examine the long-term benefit and risk of pexidartinib.

Chondroid Synoviocytic Neoplasm: A Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of a Distinctive Tumor of Synoviocytes.

Tumors resembling tenosynovial giant cell tumor (TGCT) but additionally forming chondroid matrix are rare and most often involve the temporomandibular joint (TMJ). We studied 21 tumors consisting of synoviocytes (large, eosinophilic mononuclear cells containing hemosiderin) and chondroid matrix to better understand these unusual neoplasms. The tumors occurred in 10 males and 11 females, in the age group of 31 to 80 years (median, 50 years) and involved the TMJ region (16), extremities (4), and spine (1). As in conventional TGCT, all were composed of synoviocytes, small histiocytes, foamy macrophages, siderophages, and osteoclast-like giant cells in variably hyalinized background. Expansile nodules of large, moderately atypical synoviocytes were present, in addition to "chondroblastoma-like," "chondroma-like," or "phosphaturic mesenchymal tumor-like" calcified matrix. The synoviocytes expressed clusterin (17/19) and less often desmin (3/15). The tumors were frequently CSF1 positive by chromogenic in situ hybridization (8/13) but at best weakly positive for CSF1 by immunohistochemistry (0/3). Background small histiocytes were CD163 positive (12/12). All were FGF23 negative (0/10). Cells within lacunae showed a synoviocytic phenotype (clusterin positive; S100 protein and ERG negative). RNA-Seq was successful in 13 cases; fusions were present in 7 tumors, including FN1::TEK (5 cases); FN1::PRG4 (2 cases); and MALAT1::FN1, PDGFRA::USP35, and TIMP3::ZCCHC7 (1 case each). Three tumors contained more than 1 fusion (FN1::PRG4 with TIMP3::ZCCHC7, FN1::TEK with FN1::PRG4, and FN1::TEK with MALAT1::FN1). Clinical follow-up (17 patients; median follow-up duration 38 months; range 4-173 months) showed 13 (76%) to be alive without evidence of disease and 4 (24%) to be alive with persistent/recurrent local disease. No metastases or deaths from disease were observed. We conclude that these unusual tumors represent a distinct category of synoviocytic neoplasia, which we term "chondroid synoviocytic neoplasm," rather than simply ordinary TGCT with cartilage. Despite potentially worrisome morphologic features, they appear to behave in at most a locally aggressive fashion.

Micro-CT, Mechanical, and Histological Examination of the Effect of Local Adjuvants on Porcine Cortical Bone Following Intralesional Curettage of Bone Tumors.

BACKGROUND AND OBJECTIVES: Curettage is the removal of a tumor from the bone while preserving the surrounding healthy cortical bone, and is associated with higher rates of local recurrence. To lower these rates, curettage should be combined with local adjuvants, although their use is associated with damage to nearby healthy bone. OBJECTIVE: The purpose of this analysis is to determine the effect of local adjuvants on cortical porcine bone by using micro-computed tomography (micro-CT) along with histological and mechanical examination. METHODS: Local adjuvants were applied to porcine specimens under defined conditions. To assess changes in bone mineral density (BMD), a micro-CT scan was used. The pixel gray values of the volume of interest (VOI) were evaluated per specimen and converted to BMD values. The Vickers hardness test was employed to assess bone hardness (HV). The depth of necrosis was measured histologically using hematoxylin and eosin-stained tissue sections. RESULTS: A noticeable change in BMD was observed on the argon beam coagulation (ABC) sample. Comparable hardness values were measured on samples following electrocautery and ABC, and lowering of bone hardness was obtained in the case of liquid nitrogen. Extensive induced depth of necrosis was registered in the specimen treated with liquid nitrogen. CONCLUSION: This study determined the effect of local adjuvants on cortical bone by using micro-CT along with histological and mechanical examination. Phenolization and liquid nitrogen application caused a decrease in bone hardness. The bone density was affected in the range of single-digit percentage values. Liquid nitrogen induced extensive depth of necrosis with a wide variance of values.

Giant Cell Granuloma of the Jaws and Keratin-Positive Giant Cell-Rich Tumor of Bone and Soft Tissue.

BACKGROUND: Different giant cell-rich tumors may occur in the jaws. Recently, a new condition known as keratin-positive giant-cell rich tumor harboring recurrent HMGA2::NCOR2 fusions has been described. Interestingly, the mononuclear cells of this tumor are immunoreactive with the AE1/AE3 keratin. Considering the similarities of central and peripheral giant cell granuloma of the jaws with the keratin-positive giant cell-rich tumor of the soft tissue and bone, we hypothesized whether the keratin-positive tumors could also occur in the maxillary bones. METHODS AND RESULTS: An immunohistochemical investigation of AE1/AE3 in a cohort of 16 cases of peripheral and central giant cell granuloma of the jaws was carried out. None of the cases was keratin-positive. CONCLUSIONS: Although no immunopositivity for keratin was observed in the present giant cell granulomas cohort, we cannot completely exclude the possibility of keratin-positive giant cell-rich tumors occurring in the jaws. Therefore, oral pathologists should be aware about this condition and further studies using cohorts from different laboratories are necessary.

MANEUVER: A Phase III study of pimicotinib to assess efficacy and safety in tenosynovial giant cell tumor patients.

Tenosynovial giant cell tumor (TGCT) is a rare, locally invasive soft tissue tumor arising from the synovium of joints, bursa and tendon sheaths and is associated with the overexpression of the colony-stimulating factor 1 (CSF-1) gene. Pimicotinib is an orally available, highly selective and potent small molecule CSF-1 receptor (CSF-1R) inhibitor with robust efficacy and safety profile in patients with TGCT and is under development in multiple diseases. In an open-label Phase I study in patients with TGCT not amenable to surgery, pimicotinib showed superior efficacy and safety. In this article, we elucidate the rationale and study design of the multi-region Phase III MANEUVER trial (NCT05804045), which is designed to assess the efficacy and safety of pimicotinib in patients with TGCT not amenable to surgical resection in Asia, North America and Europe.

Tenosynovial giant cell tumor (TGCT) is a rare soft tissue tumor which grows in the soft tissues around joints or parts of the body used for movement. It is caused by high levels of a type of protein called CSF-1. Even though surgery is a preferred treatment option, some patients may be unable to have surgery because of where the tumor is, how complicated it is, or the risk of serious problems or illness after the surgery. Therefore, new treatments that are safe, effective and that help people live well are still needed for this disease. Pimicotinib is a medicine which blocks CSF-1, and researches have shown that it is safe and effective for treating TGCT in smaller, early study. To confirm these results, researchers have started a larger study, known as MANEUVER, in some parts of Asia, North America and Europe. This study will confirm if pimicotinib is safe and effective in patients with TGCT who may not be able to have surgery.Clinical Trial Registration: NCT05804045 (ClinicalTrials.gov).

The MOTION study: a randomized, phase III study of vimseltinib for the treatment of tenosynovial giant cell tumor.

Tenosynovial giant cell tumor (TGCT) is a rare, locally aggressive neoplasm that occurs in the synovium of joints, bursae, or tendon sheaths and is caused by upregulation of the CSF1 gene. Vimseltinib is an oral switch-control tyrosine kinase inhibitor specifically designed to selectively and potently inhibit the CSF1 receptor. Here, we describe the rationale and design for the phase III MOTION trial (NCT05059262), which aims to evaluate the efficacy and safety of vimseltinib in participants with TGCT not amenable to surgical resection. In part 1, participants are randomized to receive vimseltinib 30 mg twice weekly or matching placebo for ≤24 weeks. Part 2 is a long-term treatment phase in which participants will receive open-label vimseltinib.

Tenosynovial giant cell tumor (or TGCT) is a rare, noncancerous tumor that grows in the soft tissue lining the spaces of joints and bursae (fluid-filled sacs that work to reduce friction in the joints). These tumors are linked to increased levels of a protein called CSF1. While this condition is typically treated with surgery, some patients may not be candidates for surgical removal of the tumor due to factors such as location or complexity of the tumor; therefore, drug treatments are needed to help these patients. Vimseltinib is an investigational oral drug specifically designed to inhibit the receptor to which the CSF1 protein binds. In this article, we describe the rationale and design for a phase III clinical trial that will test how well vimseltinib works in participants with TGCT who are not candidates for surgery. In the first part of the study, participants are randomly assigned to receive vimseltinib 30 mg twice weekly or a matching placebo (inactive substance) for up to 24 weeks. This first part is blinded, so participants will not know if they are receiving vimseltinib or the placebo. The second part of the study is a long-term treatment phase in which all participants will receive vimseltinib (unblinded). Clinical Trial Registration: NCT05059262 (ClinicalTrials.gov).

TURALIO® Risk Evaluation and Mitigation Strategy Program (tREMS): 3-year retrospective hepatic safety assessment.

Aim: Hepatic safety data assessment from the TURALIO® (pexidartinib) Risk Evaluation and Mitigation Strategy (tREMS) Program.Methods: Retrospective 3-year assessment (August 2019 to June 2022) of hepatic events from the TURALIO® (pexidartinib) Risk Evaluation and Mitigation Strategy Program.Results: A total of 451 patients, 369 prescribers, 2 wholesalers/distributors and 2 pharmacies were enrolled and certified. Twenty-one (4.7%) patients met the criteria for a hepatic adverse event or laboratory abnormality suggestive of serious and potentially fatal liver injury, all with onset within 2 months of therapy. No new hepatic safety signals were identified.Conclusion: Results are consistent with the phase 3 ENLIVEN trial data. Liver enzyme monitoring, combined with early intervention, including dose modification and discontinuation, conducted in patients treated with pexidartinib mitigate the risk of potential hepatotoxicity.

Safety findings from the 3-year data collected in the TURALIO^® Risk Evaluation and Mitigation Strategy ProgramPexidartinib (TURALIO^®) is an oral drug that is used to treat adults with tenosynovial giant cell tumor (TGCT) that cannot be fixed with surgery. TGCTs are rare, noncancerous tumors that cause pain, stiffness and difficulty moving. Pexidartinib works by blocking a protein that helps these tumors grow. Before pexidartinib, there were no good treatments for TGCT and surgery often could not remove all the tumors, so they would frequently grow back.Pexidartinib was approved in 2019 after a clinical trial showed it worked well in adults with TGCT. However, pexidartinib can sometimes cause serious liver harm for some patients. To handle this risk, a program called the tREMS (TURALIO^® Risk Evaluation and Mitigation Strategy) was established to ensure that pexidartinib is used safely.The tREMS Program teaches doctors, pharmacists and patients about the safe use of pexidartinib and potential liver risks and enrolls patients in a registry to watch their health. Doctors and pharmacies must be certified, and patients need regular liver tests. In the first 3 years, 451 patients and 369 doctors joined the program. Unintended liver issues were found in around 5% of patients, a rate that is about the same as that seen in pexidartinib clinical trials, and no new safety concerns were found. About half of patients with liver issues could reverse them by stopping pexidartinib. No patient had permanent liver damage, needed a transplant or died from liver problems. These results show that the tREMS Program is working well to keep patients with TGCT safe while taking pexidartinib.

Real-world drug utilization and treatment patterns in patients with tenosynovial giant cell tumors in the USA.

Aim: Real-world treatment patterns in tenosynovial giant cell tumor (TGCT) patients remain unknown. Pexidartinib is the only US FDA-approved treatment for TGCT associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Objective: To characterize drug utilization and treatment patterns in TGCT patients. Methods: In a retrospective observational study using IQVIA's linked prescription and medical claims databases (2018-2021), TGCT patients were stratified by their earliest systemic therapy claim (pexidartinib [N = 82] or non-FDA-approved systemic therapy [N = 263]). Results: TGCT patients treated with pexidartinib versus non-FDA-approved systemic therapies were predominantly female (61 vs 50.6%) and their median age was 47 and 54 years, respectively. Pexidartinib-treated patients had the highest 12-month probability of remaining on treatment (54%); 34.1% of pexidartinib users had dose reduction after their first claim. Conclusion: This study provides new insights into the unmet need, utilization and treatment patterns of systemic therapies for the treatment of TGCT patients.

Treatment patterns in patients with tenosynovial giant cell tumors in the USAThis database study is the first investigation of how drugs are used to treat patients with tenosynovial giant cell tumor (TGCT) in the real world. We researched adult TGCT patients from IQVIA's prescription and medical claims databases who started treatment with pexidartinib (N = 82) or other non-US FDA-approved systemic therapies (N = 263). The patients included in this analysis were mostly women (61.0 and 50.6%) and their median age was 47 and 54 years for pexidartinib and other non-FDA-approved systemic therapies, respectively. The patients treated with pexidartinib were most likely to remain on treatment (54.0%) at the end of the first year. Most patients (79.3%) started pexidartinib treatment at a total daily dose of 800 mg/day, as per the product label. Only 34.1% of patients had reduced medication dose during follow-up. Of note, this study found that TGCT patients were treated with other systemic therapies which remain unproven to be safe and effective in medical studies of TGCT. Given the unmet need, and with pexidartinib being the only approved systemic treatment in USA, there is an opportunity for the larger population of adult TGCT patients to benefit from its use. Further research is needed to identify barriers for access to pexidartinib and treatment of TGCT patients.

The diagnostic and prognostic value of tartrate-resistant acid phosphatase isoform 5b for giant cell tumor of bone.

BACKGROUND: Serum level of tartrate-resistant acid phosphatase 5b (TRACP5b) is an excellent serum marker of bone resorption. In patients with giant cell tumor of bone (GCTB), TRACP5b levels are reportedly elevated. This study investigated whether TRACP5b could be a diagnostic serum marker and be useful for detecting postoperative disease progression for GCTB. METHODS: Cohort 1: We abstracted data from 120 patients with TRACP5b measurements from our database: 49 patients with GCTB and 71 patients non-GCTB. We compared serum TRACP5b values between the GCTB and non-GCTB groups. Cohort 2 included 47 patients with GCTB who had more than 6 months of follow-up and multiple TRACP5b values. For patients with local recurrence, TRACP5b change rate was calculated by comparing the TRACP5b value just before progression (a) with the value at the time of progression (b): Change rate = [(b)-(a)]/(a). In the non-progression group, the change rate was calculated from the two consecutive TRACP5b values, (c) and (d): Change rate =[(c)-(d)]/(c). We compared TRACP5b change rates between the progression and non-progression groups. RESULTS: Cohort 1: The GCTB group had a significantly higher mean TRACP5b value (1756 ± 2021 mU/dL) than the non-GCTB group (415 ± 219 mU/dL) (p < 0.0001). Cohort 2: The mean TRACP5b change rate of the progression group was significantly higher than the non-progression group (8.53 ± 8.52 and 0.24 ± 0.27, respectively; p < 0.0001). CONCLUSION: TRACP5b is a useful diagnostic marker in GCTB. The rate of change in serum TRACP5b values is a highly sensitive marker for predicting local recurrence in GCTB.

Nonfamilial cherubism in a 6-month-old infant: a case report.

BACKGROUND: Cherubism is known as a very rare autosomal dominant familial disorder of childhood caused by a mutation in the SH3BP2 gene on 4p16.3. It has not yet been observed at birth and is usually diagnosed in children aged 2-7. Here, we present a non-hereditary case of cherubism at a very early age. CASE PRESENTATION: A 6-month-old girl presented with bilateral progressive jaw enlargement. On physical examination, bilateral asymmetrical jaw enlargement, predominantly on the left side, and some enlarged, non-tender, mobile submandibular lymph nodes were detected. No other abnormality was observed. Further investigations with radiology suggested cherubism and Burkitt's lymphoma as differential diagnoses. Later on, histopathologic evaluations were suggestive of cherubism. No surgical interventions were indicated, and the child is on regular follow-ups. CONCLUSION: Non-hereditary Cherubism, despite scarcity, can present in children below two years of age, even as early as the beginning of primary dentition. Accurate and swift diagnosis is essential to avert physical and psychological complications. Our case report shows the importance of keeping cherubism in mind as a differential diagnosis of bone disease, even in children under a year old, and the value of interdisciplinary collaboration in dealing with rare genetic disorders.

Denosumab-induced bone changes in a child: a case report.

We present the case of a 9-year-old girl who developed striking bone changes following two years of denosumab therapy for giant cell lesions of the jaw.

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.

Diagnosis and monitoring denosumab therapy of giant cell tumors of bone: radiologic-pathologic correlation.

OBJECTIVE: To determine the value of CT and dynamic contrast-enhanced (DCE-)MRI for monitoring denosumab therapy of giant cell tumors of bone (GCTB) by correlating it to histopathology. MATERIALS AND METHODS: Patients with GCTB under denosumab treatment and monitored with CT and (DCE-)MRI (2012-2021) were retrospectively included. Imaging and (semi-)quantitative measurements were used to assess response/relapse. Tissue samples were analyzed using computerized segmentation for vascularization and number of neoplastic and giant cells. Pearson's correlation/Spearman's rank coefficient and Kruskal-Wallis tests were used to assess correlations between histopathology and radiology. RESULTS: Six patients (28 ± 8years; five men) were evaluated. On CT, good responders showed progressive re-ossification (+7.8HU/month) and cortical remodeling (woven bone). MRI showed an SI decrease relative to muscle on T1-weighted (-0.01 A.U./month) and on fat-saturated T2-weighted sequences (-0.03 A.U./month). Time-intensity-curves evolved from a type IV with high first pass, high amplitude, and steep wash-out to a slow type II. An increase in time-to-peak (+100%) and a decrease in Ktrans (-71%) were observed. This is consistent with microscopic examination, showing a decrease of giant cells (-76%), neoplastic cells (-63%), and blood vessels (-28%). There was a strong statistical significant inverse correlation between time-to-peak and microvessel density (ρ = -0.9, p = 0.01). Significantly less neoplastic (p = 0.03) and giant cells (p = 0.04) were found with a time-intensity curve type II, compared to a type IV. Two patients showed relapse after initial good response when stopping denosumab. Inverse imaging and pathological findings were observed. CONCLUSION: CT and (DCE-)MRI show a good correlation with pathology and allow adequate evaluation of response to denosumab and detection of therapy failure.

Chronic hearing loss turns out being a calcified chondroid mesenchymal neoplasm with FN1::FGFR2 fusion.

A 53 year old female presented with a six-year history of right-sided slow deterioration in hearing and a feeling of pressure in the right ear. The patient had not experienced any pain but reported some paresthesia of the right half of the tongue, whereas no further other cranial nerve deficits were evident. The otoscopy was unremarkable as well as the rest of the clinical ENT examination except for a slight asymptomatic swelling of the right cheek. Imaging findings showed an expansive tumor infiltrating and destroying the right lateral skull base. The tumor was partially composed of cystic/regressive lesions with high contrast media uptake. The tumor had high-signal intensity with water-sensitive sequences (T2w) and was hypointense on T1w images. We performed a tumor resection via a transparotideal-infratemporal approach. Histologically, the tumor was composed of granular variably calcified chondroid matrix with extensive regressive changes and granulation-like tissue reaction associated with calcinosis and crystal deposition. Molecular analysis of the tumor via the TruSight- RNA-Fusion panel detected a fusion involving FN1::FGFR2, consistent with "calcified chondroid mesenchymal neoplasm" (CCMN), a rare tumor entity recently defined by Liu et al 2021. In regular follow-up care no residual tumor has been detected in imaging studies (MRI and CT) within 2 years and 4 months. The biology and consequently the radio sensitivity cannot be defined precisely since long term results are missing due to the first description of this entity in 2021. As a consequence, surgical resection is recommended as the treatment of choice. Thorough clinical and radiological follow-up is mandatory as local recurrences are to be expected due to the infiltrative behavior. In case of a loco regional recurrence the fusion with FGFR2 may represent a therapeutic option for a targeted therapy on molecular level.

Reduced recurrence rate and comparable functionality after wide resection and reverse total shoulder arthroplasty with allograft-prosthetic composite versus curettage for proximal humeral giant cell tumor: a multicenter retrospective study.

BACKGROUND: Giant cell tumors of bone (GCTBs) are rare, aggressive tumors, and the proximal humerus is a relatively rare location for GCTBs; limited evidence exists on which surgical approaches and reconstruction techniques are optimal. In the largest case series to date, we evaluated the recurrence rate of proximal humeral GCTBs and the functional outcomes of different resection and reconstruction options in this multicenter study. METHODS: All 51 patients included in this study received initial surgical treatment for proximal humeral GCTBs from January 2007 to December 2020, with a minimum 2-year follow-up period. Local recurrence and functional outcomes were statistically analyzed in relation to demographic, clinical, and primary surgical variables. Functional outcomes were reported by patients and were assessed by the Musculoskeletal Tumor Society score and QuickDASH instrument (shortened version of the Disabilities of the Arm, Shoulder and Hand instrument). RESULTS: The mean follow-up period was 81.5 months (range, 30-191 months), and the overall recurrence rate was 17.6% (9 of 51 patients). The majority of recurrences (n = 7) occurred in the first 2 years of follow-up. The intralesional curettage group (n = 23) showed a statistically significant difference in the recurrence rate compared with the en bloc resection group (n = 28) (34.8% vs. 3.6%, P = .007). Among shoulders receiving en bloc resection, 16 were reconstructed with hemiarthroplasty; 8, reverse total shoulder arthroplasty (rTSA) with allograft-prosthetic composite (APC) reconstruction; and 4, arthrodesis. On the basis of intention-to-treat analysis, the mean functional Musculoskeletal Tumor Society scores of the groups undergoing curettage, rTSA with APC, hemiarthroplasty, and arthrodesis were 26.0 ± 3.1, 26.0 ± 1.7, 20.3 ± 2.8, and 22.5 ± 1.3, respectively (P < .001 [with P < .001 for curettage vs. hemiarthroplasty and P = .004 for rTSA with APC vs. hemiarthroplasty]) and the mean QuickDASH scores were 14.0 ± 11.0, 11.6 ± 4.5, 33.1 ± 11.8, and 21.6 ± 4.7, respectively (P < .001 [with P < .001 for curettage vs. hemiarthroplasty and P = .003 for rTSA with APC vs. hemiarthroplasty]). CONCLUSIONS: On the basis of our data, en bloc resection followed by reverse shoulder arthroplasty showed a lower recurrence rate and no significant difference in functional outcome scores for proximal humeral GCTBs compared with intralesional curettage. Therefore, we believe that rTSA with APC may be reasonable for the initial treatment of proximal humeral GCTBs.

Sonographic features of diffuse giant cell tumor of the tendon sheath in the shoulder: A case report.

A middle-aged woman presented to our hospital with a chief complaint of a mass on the left shoulder for 1 year. The initial lump was small with no pain or tenderness, and the patient had not sought medical attention for numbness in the left shoulder. Clinical examination showed a mass on the left shoulder measuring 11 × 8 × 3 cm approximately with no apparent skin damage or ecchymosis. No limitations in left shoulder joint movements were observed, and the patient exhibited normal movement of the left elbow joint, wrist joint, and metacarpophalangeal joint. Moreover, the left radial artery was palpable.

A novel colony-stimulating factor 1 (CSF1) translocation involving human endogenous retroviral element in a tenosynovial giant cell tumor.

Tenosynovial giant cell tumors (TSGCTs) are rare tumors arising in tendons or the synoviae of joints and bursae. The localized type is benign while the diffuse type shows expansive growth leading to greater morbidity and is therefore considered locally aggressive. Typical recurrent chromosomal aberrations are found in the majority of TSCGT and the CSF1 gene is frequently involved. In this article, we describe a newly identified gene fusion mediated by an inversion in a case of diffuse TSGCT. Multicolor-fluorescence in situ hybridization (FISH) molecular karyotyping identified a pericentric inversion of chromosome 1 in 7 out of 17 analyzed cells 46,XX,inv(1)(p13.3q24.3) [7]/46,XX [10], and with interphase FISH the involvement the CSF1 locus was detected. After performing transcriptome sequencing analysis for fusion detection, only one out of five fusion gene algorithms detected a fusion involving the CSF1 gene product. The resulting chimera fuses a sequence from a human endogenous retrovirus (HERV) gene to CSF1 Exon 6 on chromosome 1, abrogating the regulatory element of the 3' untranslated region of the CSF1 gene. This new translocation involving Exon 6 of the CSF1 gene fused to 1q24.1, supports the hypothesis that a mutated CSF1 protein is likely to play a vital role in the pathogenesis of TSGCT. The role of the HERV partner identified as a translocation partner, however, remains unclear. Our data add to the complexity of involved translocation partners in TSGCT and point to the potential difficulty of identifying fusion partners in tumor diagnostics using transcriptome sequencing when HERV or other repeat elements are involved.

Treatment Modalities for Refractory-Recurrent Tenosynovial Giant Cell Tumor (TGCT): An Update.

Background and Objectives: Tenosynovial giant cell tumor (TGCT) is a rare, locally aggressive, benign neoplasm arising from the synovium of joints, tendon sheaths, and bursa. There are two main subtypes of TGCT: localized-type TGCT(L-TGCT) and diffuse-type TGCT (D-TGCT). While surgical excision is still considered the gold standard of treatment, the high recurrence rate, especially for D-TGCT, may suggest the need for other treatment modalities. Materials and Methods: This study reviews current literature on the current treatment modalities for refractory-relapsed TGCT disease. Results: The gold standard of treatment modality in TGCT remains surgical excision of the tumor nevertheless, the elevated recurrence rate and refractory disease, particularly in D-TGCT indicates and underscores the necessity for additional treatment alternatives. Conclusions: TGCT is a benign tumor with inflammatory features and a potential destructive and aggressive course that can lead to significant morbidity and functional impairment with a high impact on quality of life. Surgical resection remains the gold standard current treatment and the optimal surgical approach depends on the location and extent of the tumor. Systemic therapies have been recently used for relapsed mainly cases.

Giant Cell Tumor of the Tendon Sheath of the Hand: Analysis of Factors Impacting Recurrence.

Background Giant cell tumors of the tendon sheath (GCTTS) of the hand are considered the second most common benign tumors of the hand after ganglion cysts. Excision biopsy is considered the standard treatment at present. They are notorious for having a very high rate of recurrence as given in many studies. Many factors are said to be associated with recurrence of the tumors. The goal of this study is to evaluate the long-term results of a series of 48 patients operated on at a single institute and to find out if there is any correlation between the proposed risk factors with recurrence. Methods A retrospective analysis was done in cases of GCTTS operated on between 2015 and 2021. The patients were invited for follow-up for a minimum of 2 years, and the patient files were reviewed. Further data were collected at follow-up including recurrence, range of movement, sensation, skin necrosis, scarring, and digital neuropathy. A data analysis was done. The correlation between the proposed risk factors and recurrence was calculated with the Pearson correlation coefficient. A p -value of less than 0.05 was considered statistically significant. Results During the 6 years, 48 patients were operated on. Recurrence was observed in eight patients (16%) at an average of 38.7 months from the time of surgery. Of the risk factors, tumors with satellite nodules and tumor adjacency to joint correlated significantly with recurrence. No complications were observed during follow-up. Conclusion GCTTS of the hand has a high propensity to recur. The presence of satellite nodules and proximity to interphalangeal joints are two important risk factors for recurrence. Magnification during surgery ensures complete excision of the tumor and reduces the chance of recurrence.