Atypical Presentation of Tenosynovial Giant Cell Tumor on the Hallucal Flexor Tendon Sheath: A Case Report.

Tenosynovial giant cell tumor (TGCT) is a rare type of neoplasm that may be locally aggressive but is most often benign and can be divided into two subtypes: localized and diffuse. It tends to develop in the joints, bursae, and tendon sheaths primarily in the digits of the hand and less commonly in the forefoot. This soft-tissue mass has many possible differential diagnoses, including lipoma, ganglion cyst, plantar fibroma, and various sarcomas; surgical excision is usually indicated to reach a definitive diagnosis and rule out malignancy. We report a rare case of a 30-year-old woman with atypical plantar hallucal pain and a palpable mass on the plantar lateral aspect of the left hallux. Surgical excision and histopathologic evaluation confirmed a TGCT of the left hallucal flexor tendon sheath. Although it bears clinical resemblance to several other soft-tissue masses, TGCT has numerous pathognomonic features evident with advanced imaging and histologic analysis that help the physician obtain an accurate diagnosis and proceed with appropriate treatment.

Localized type tenosynovial giant cell tumor with metastases to lungs and pleura: a case report and literature review.

BACKGROUND: Tenosynovial giant cell tumor is a rare soft tissue tumor of the synovium of joint, bursae, or tendon sheath. It is divided into localized or diffuse types on the basis of the growth pattern. Localized tenosynovial giant cell tumors are usually benign and treated successfully by excision. Diffuse tenosynovial giant cell tumors, in contrast to localized type, can destroy bone and cartilage and are associated with frequent local recurrences and distant metastasis. Localized type tenosynovial giant cell tumors rarely metastasize to distant organs. Here, we report a case of localized tenosynovial giant cell tumor presenting with lung metastases and systematically review literature. CASE PRESENTATION: A 55-year-old Asian male presented with a dry cough, right-sided chest pain and progressive dyspnea for 1 month. At 18 months before this presentation, he had undergone excision of a painless swelling on his right index finger. The swelling recurred within 3 months of excision, and a biopsy was then suggestive of a giant cell tumor. Given the suspicion of a giant cell tumor, a wide excision of the lesion was performed and the excisional biopsy was consistent with a diagnosis of tenosynovial giant cell tumor, localized type. At admission to our hospital, the patient had tachypnoea and absent breath sounds on the right side. A chest radiograph showed a right-sided pleural effusion with a homogenous opacity in the left mid-zone. A contrast-enhanced computed tomography of the chest and abdomen showed right massive pleural effusion and bilateral multiple lobulated heterogeneously enhancing pleural-based masses with areas of internal calcification. Pleural fluid analysis revealed an exudate with no malignant cells on cytology. A lung biopsy showed osteoclast-like giant cells and mononuclear spindle cells with areas of hemorrhage and necrosis, suggesting tenosynovial giant cell tumor metastasis. A final diagnosis of localized type tenosynovial giant cell tumor of the right index finger with metastases to the lungs and pleura was made. The patient passed away after receiving three cycles of denosumab injection owing to progressive disease. CONCLUSION: Lung metastasis is extremely rare in patients with localized tenosynovial giant cell tumor. The survival is usually poor in patients with lung metastasis. A close follow-up of patients with localized type tenosynovial giant cell tumor is necessary for early detection of pleuropulmonary complications.

Diffuse-Type Tenosynovial Giant Cell Tumor An Update of Current Management Strategies.

Diffuse-type giant cell tumor (Dt-GCT), formerly known as pigmented villonodular synovitis, is the more aggressive entity belonging to the spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae, and tendon sheaths. Diffuse-type giant cell tumor's importance stems from its local aggressiveness and sequelae if left untreated. This review briefly describes Dt-GCT's clinical features, its imaging and pathology findings, and provides an extensive discussion of its available treatments. The management approaches of Dt-GCT can be divided into surgical management and non-surgical management, which includes radiation therapy or more novel molecular and biologic therapies. We also present an algorithm based on disease presentation and site involved to guide treatment.

CSF1R Inhibition in Patients with Advanced Solid Tumors or Tenosynovial Giant Cell Tumor: A Phase I Study of Vimseltinib.

PURPOSE: Tenosynovial giant cell tumor (TGCT) is a locally aggressive neoplasm caused by dysregulation of the colony-stimulating factor 1 (CSF1) gene and overexpression of the CSF1 ligand. Surgery is the standard of care for most patients, but there are limited treatment options for patients with TGCT not amenable to surgery. This study evaluates vimseltinib, an investigational, oral, switch-control tyrosine kinase inhibitor designed to selectively and potently inhibit the CSF1 receptor. PATIENTS AND METHODS: This first-in-human, multicenter, open-label phase I/II study of vimseltinib in patients with malignant solid tumors (N = 37) or TGCT not amenable to surgery (N = 32) followed a pharmacologically guided 3 + 3 study design (NCT03069469). The primary objectives were to assess safety and tolerability, determine the recommended phase II dose, and characterize the pharmacokinetics; exploratory objectives included pharmacodynamics and efficacy. RESULTS: Vimseltinib was well tolerated; the majority of non-laboratory treatment-emergent adverse events were of grade 1/2 severity. There was no evidence of cholestatic hepatotoxicity or drug-induced liver injury. The recommended phase II dose was determined to be 30 mg twice weekly (no loading dose), and vimseltinib plasma exposure increased with the dose. In patients with TGCT, the median treatment duration was 25.1 months (range, 0.7-46.9), and the objective response rate as assessed by independent radiological review using RECIST version 1.1 was 72%. CONCLUSIONS: Vimseltinib demonstrated long-term tolerability, manageable safety, dose-dependent exposure, and robust antitumor activity in patients with TGCT not amenable to surgery.

Fine-needle aspiration cytology of diffuse type tenosynovial giant cell tumor with malignant trasformation and review of literature.

Tenosynovial giant cell tumors (TGCTs) arise from the synovium of joint, bursa, and tendon sheath. Diffuse type often affects large joints, has higher recurrence rates, metastases, and malignant transformation potential compared to the localized type. The cytopathology of TGCT, a fibrohistiocytic neoplasm distinct from other giant cell-rich soft tissue tumors, is rarely reported. Here we describe cytomorphology of a case of TGCT that was initially diagnosed on fine-needle aspiration cytology (FNAC) consisting of a mixture of singly scattered polygonal or spindle mononuclear cells with hemosiderin laden macrophages, inflammatory cells, and a population of multinucleated osteoclast-like giant cells. Persistent symptoms and repeat excision were consistent with high-grade malignant transformation of the TGCT. Atypical cytologic features in a recurrent, infiltrative, or a metastatic lesion should raise suspicion for malignancy.

Tenosynovial giant cell tumor: case report and molecular investigation.

Tenosynovial giant cell tumor is a benign neoplasm arising from the synovium of joints, including the temporomandibular joint (TMJ). Despite its benign nature, these tumors may exhibit aggressive behavior. A 57-year-old woman with a swollen, hardened area in the left TMJ was referred to the university´s clinic. The diagnosis of tenosynovial giant cell tumor was made based on the presence of hyperplastic synovial lining containing mononuclear and giant cells, hemorrhagic areas, hemosiderin deposits, and calcification foci in the biopsy. A low condylectomy was performed, and histopathologic analysis of the surgical piece upheld the diagnosis. Due to histopathologic resemblance with other giant cell-rich lesions (giant cell granuloma of the jaws, brown tumor of hyperparathyroidism, and non-ossifying fibroma) for which signature mutations are known, mutational analysis of KRAS, FGFR1, and TRPV4 genes was conducted. The results revealed wild-type sequences for all the mutations tested, thereby supporting the diagnosis of tenosynovial giant cell tumor.

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 effect of surgical factors on recurrence of tendon sheath giant cell tumours.

In this retrospective study, we evaluated the impact of tumour-related and surgical factors on the recurrence of giant cell tumours of tendon sheath. A total of 95 patients were treated at our institution between February 2012 and March 2021. We identified the factors most likely to be associated with recurrence from evaluation of classification, neurovascular invasion, bone erosion and joint invasion. Based on these criteria, we identified 49 patients with a high risk of recurrence. Of the 95 patients, recurrence was observed in 17. Among the 49 patients classified as high-risk, 13 were found to have recurrence. This study demonstrates that recurrence is more common in the high-risk patient group.Level of evidence: IV.

Arthroscopic Excision of a Localized Tenosynovial Giant Cell Tumor of the Knee: A Case Report.

BACKGROUND AND AIM: A tenosynovial giant cell tumor (TGCT) is a proliferative lesion of the synovial membrane of the joints, tendon sheaths and/or bursae. There are two described subtypes, including the localized and diffuse forms. A TGCT can also be intraarticular or extraarticular. An intraarticular localized tenosynovial giant cell tumor (L-TGCT) of the knee is characterized by nodular hyperplasic synovial tissue that can remain asymptomatic for a long time, but as the mass grows, it may cause mechanical symptoms that may require surgical treatment. The aim of our study is to present a rare case of an L-TGCT of the knee joint treated with an arthroscopic excision. CASE REPORT: We describe the case of a 17-year-old female with pain, swelling and knee locking in the absence of trauma. The magnetic resonance imaging (MRI) displayed a well-circumscribed small mass in the anterior medial compartment, adherent to the infrapatellar fat pad. The lesion presented the typical MRI characteristics of an intraarticular localized TGCT. The patient was treated with an arthroscopic mass removal and partial synovectomy. The gross pathology showed an ovoid nodule that was covered by a fibrous capsule; a histopathology examination confirmed the diagnosis. The patient was able to return to normal daily activities one month after surgery; at the three-year follow-up, she was free of symptoms with no evidence of disease on the MRI. CONCLUSION: In patients with a small-dimension L-TGCT in the anterior compartment of the knee that presents an MRI pattern and causes mechanical symptoms, an arthroscopic en-bloc excision can be performed that results in good outcomes and a rapid return to preinjury levels.

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.

Medium-term Outcomes of Excision Using Surgical Microscope of Tenosynovial Giant Cell Tumors of the Hand.

BACKGROUND/AIM: The recurrence rate following the excision of tenosynovial giant cell tumors (TSGCT) of the hand is very high. Intraoperative application of a surgical microscope has been reported. However, to date, there are no reports of medium-term outcomes related to this technique. This study aimed to evaluate the medium-term outcomes of tumor excision using surgical microscope for TSGCT of the hand. PATIENTS AND METHODS: A total of 27 patients, who underwent an initial surgery for histologically-confirmed TSGCT of the hand, between 2008 and 2020, were included and evaluated. The mean follow-up time postoperatively was 6.8 years. Tumor recurrence and preoperative tumor characteristics were assessed. RESULTS: All tumors were adherent to tendons, tendon sheaths, neurovascular structures or periarticular ligaments and capsules. Bony lesions were observed in 11 tumors. The surgical microscope was used in 13 tumors. Recurrences were observed in three tumors (overall recurrence rate: 11%). Tumor characteristics were similar in both groups, but the recurrence rate in the group treated using the surgical microscope was 0%, whereas the recurrence rate in the group treated without the surgical microscope was 21%. Re-operations using the surgical microscope for recurrent tumors were performed, without recurrence postoperatively. CONCLUSION: Among patients with TSGCT of the hand treated with tumor excision using the surgical microscope, the postoperative recurrence rate was 0%. Based on the results of this study, the surgical microscope might be used for excision of TSGCTs of the hand.

A Rare Clinical Presentation With a Difficult Imaging Diagnosis of an Intra-articular Clear Cell Sarcoma of the Knee.

ABSTRACT: Clear cell sarcoma, a highly aggressive cell sarcoma with melanotic differentiation, typically occurs in the tendon and aponeuroses of the lower extremities and rarely develops in the intra-articular region. Herein, we present an extremely rare case of clear cell sarcoma originating from the intra-articular knee and suspected as benign tumors due to the benign-looking findings on MRI and PET/CT. The image results in our case were completely consistent with a tenosynovial giant cell tumor, resulting in the misdiagnosis. For differential diagnosis, especially malignant melanoma, histopathology, including IHC and FISH, was indispensable.

Clinical retrospective analysis with a predictive model for diffused-tenosynovial giant cell tumors of the temporomandibular joint.

BACKGROUND: This study aimed to find out the characteristics in relation to tumor recurrence in diffused-tenosynovial giant cell tumor of temporomandibular joint and to develop and validate the prognostic model for personalized prediction. METHODS: From April 2009 to January 2021, patients with diffused-tenosynovial giant cell tumor of temporomandibular joint at a single center were included in this study. The clinical features and local recurrence-free survival were assessed through the expression of the Ki-67 index and colony-stimulating factor 1 receptor expression. Both univariate and multivariate analyses were performed on the prognostic factors for local recurrence-free survival. An independent predictor nomogram and pertinent tumor characteristics were included. RESULTS: The retrospective study enrolling seventy eligible patients at the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. During the follow-up time, eleven patients suffered tumor recurrence. Age was an independent risk factor for local recurrence-free survival (P = 0.032). The Ki-67 index varied significantly in different sites (P = 0.034) and tumor volume (P = 0.017). Multivariate logistic regression was used to develop the prediction model using both statistical significance and prognostic indicators. The C-index of the nomogram based on age, site, Ki-67, and colony-stimulating factor 1 receptor was 0.833. These variates provided good predicted accuracy for a nomogram on local recurrence-free survival. Diffused-tenosynovial giant cell tumor from the temporomandibular joint is extremely uncommon, and certain clinical traits are linked to the tumor proliferation index. CONCLUSIONS: We identified the risk indicators and developed a nomogram in this study to forecast the likelihood of local recurrence-free survival in patients with diffused-tenosynovial giant cell tumor from temporomandibular joint.

Tenosynovial giant cell tumor: a case report.

BACKGROUND: This case reports the synchronous diagnosis of two rare unrelated diseases; leiomyosarcoma and tenosynovial giant cell tumor of the knee. It focuses on the challenges of diagnosing tenosynovial giant cell tumor, including cognitive biases in clinical medicine that delay diagnosis. It also demonstrates the pathogenic etiology of tenosynovial giant cell tumor, evidenced by the transient deterioration of the patients' knee symptoms following the administration of prophylactic granulocyte colony-stimulating factor given as part of the chemotherapeutic regime for leiomyosarcoma. CASE PRESENTATION: A 37-year-old Caucasian man presented with a left groin lump and left knee pain with swelling and locking. Investigations including positron emission tomography-computed tomography and biopsy revealed leiomyosarcoma in a lymph node likely related to the spermatic cord, with high-grade uptake in the left knee that was presumed to be the primary site. His knee symptoms temporarily worsened each time granulocyte colony-stimulating factor was administered with each cycle of chemotherapy for leiomyosarcoma to help combat myelosuppressive toxicity. Subsequent magnetic resonance imaging and biopsy of the knee confirmed a tenosynovial giant cell tumor. His knee symptoms relating to the tenosynovial giant cell tumor improved following the completion of his leiomyosarcoma treatment. CONCLUSIONS: Tenosynovial giant cell tumor remains a diagnostic challenge. We discuss the key clinical features and investigations that aid prompt diagnosis. The National Comprehensive Cancer Network clinical practice guidelines for soft tissue sarcoma have recently been updated to include the pharmacological management of tenosynovial giant cell tumor. Our case discussion provides an up-to-date review of the evidence for optimal management of patients with tenosynovial giant cell tumor, with a particular focus on novel pharmacological options that exploit underlying pathogenesis.

A Mass on the Sole Revealing a Giant-Cell Tumor of the Tendon Sheath.

A 61-year-old woman presented with a 3-year history of painless soft-tissue mass on the right sole. The patient reported gradual growth, with a rapid increase in size over the past few months, leading to difficulty in walking. She had no history of past trauma. Examination revealed a 4-cm ovoid mass located over the ball of the foot. It was firm in consistency, with well-defined margins, a smooth surface, and an overlying normal skin (Figure 1). An ultrasound image revealed an eccentric, hypoechoic, nonvascular subcutaneous lobular mass. A magnetic resonance imaging (MRI) of the foot revealed a well-defined mass arising from the flexor tendon sheath of the right foot. The lesion was heterogeneously hyperin-tense on T1- and T2-weighted images with an avid contrast enhancement. All of the surrounding soft tissues indicated normal signal intensity patterns. There was no associated bony destruction. Histopathologic examination after complete excision of the mass established a well-circumscribed lesion composed of osteoclast-like giant cells and mononuclear cells in a hyalinized stroma, consistent with a giant cell tumor of the tendon sheath (GCT-TS) (Figure 2). There was no recurrence during a 6-month follow-up period (Figure 3).