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Diffuse-type tenosynovial giant cell tumor (TSGCT) is a rare, locally aggressive neoplasm. It most commonly occurs in the knee, followed by the hip, and has distinctive imaging features, including mass-like foci of low T2 signal intensity, "blooming" on gradient-echo MRI, and pronounced uptake on FDG PET/CT. Histologically, TSGCT demonstrates a neoplastic population of mononuclear cells admixed with hemosiderin-laden macrophages, foamy histiocytes, inflammatory cells, and osteoclast-like giant cells. In cases where diffuse-type TSGCT presents in an uncommon location or with atypical features, the imaging diagnosis may be challenging. Furthermore, because of its polymorphous appearance, it may be mistaken microscopically for other neoplastic and non-neoplastic histiocytic lesions. Herein, we present two cases of diffuse-type TSGCT presenting as large masses, and underscore the importance of radiologic-pathologic correlation for accurate diagnosis. [ABSTRACT FROM AUTHOR]

Giant cell-rich lesions represent a heterogeneous group of tumors and non-neoplastic lesions, usually arising in bone, which harbor varying number of reactive osteoclastic-type multinucleate giant cells as a common feature. Among these entities, some are confined to the head and neck region (e.g., central giant cell granuloma and mimicking lesions, i.e., peripheral giant cell granuloma and cherubism) or show a relative predilection for this region (e.g., aneurysmal bone cyst and brown tumor of hyperparathyroidism), while others are rare but associated with distinct underlying disease (e.g., giant cell tumor of bone) or histology (e.g., tenosynovial giant cell tumor of the temporomandibular joint and phosphaturic mesenchymal tumor of the jaws) when occurring in the head and neck. Collectively, these lesions pose great challenge in the pathologic diagnosis, which often requires combinatory assessment from the clinical, histopathologic, and/or molecular aspects. This review provides a summary of pertinent clinical and pathologic features and an update of recent molecular and genetic findings of these entities. The considerations in differential diagnosis as well as the effects of the emerging therapeutic RANKL-antagonizing antibody denosumab will also be addressed. [ABSTRACT FROM AUTHOR]

Summary: Background Pexidartinib, a novel, orally administered small-molecule tyrosine kinase inhibitor, has strong selectivity against colony-stimulating factor 1 receptor. This phase I, nonrandomized, open-label multiple-dose study evaluated pexidartinib safety and efficacy in Asian patients with symptomatic, advanced solid tumors. Materials and Methods Patients received pexidartinib: cohort 1, 600 mg/d; cohort 2, 1000 mg/d for 2 weeks, then 800 mg/d. Primary objectives assessed pexidartinib safety and tolerability, and determined the recommended phase 2 dose; secondary objectives evaluated efficacy and pharmacokinetic profile. Results All 11 patients (6 males, 5 females; median age 64, range 23–82; cohort 1 n = 3; cohort 2 n = 8) experienced at least one treatment-emergent adverse event; 5 experienced at least one grade ≥ 3 adverse event, most commonly (18%) for each of the following: increased aspartate aminotransferase, blood alkaline phosphatase, gamma-glutamyl transferase, and anemia. Recommended phase 2 dose was 1000 mg/d for 2 weeks and 800 mg/d thereafter. Pexidartinib exposure, area under the plasma concentration-time curve from zero to 8 h (AUC0-8h), and maximum observed plasma concentration (Cmax) increased on days 1 and 15 with increasing pexidartinib doses, and time at Cmax (Tmax) was consistent throughout all doses. Pexidartinib exposure and plasma levels of adiponectin and colony-stimulating factor 1 increased following multiple daily pexidartinib administrations. One patient (13%) with tenosynovial giant cell tumor showed objective tumor response. Conclusions This was the first study to evaluate pexidartinib in Asian patients with advanced solid tumors. Pexidartinib was safe and tolerable in this population at the recommended phase 2 dose previously determined for Western patients (funded by Daiichi Sankyo; clinicaltrials.gov number, NCT02734433). [ABSTRACT FROM AUTHOR]

Diffuse tenosynovial giant cell tumor (D-TGCT), previously known as pigmented villonodular synovitis (PVNS), is a benign, aggressive, and distracting proliferative synovial lesion. D-TGCT is commonly seen in large joints such as the knee and hip. We present the case of a 57-year-old female who initially presented with swelling on the left midfoot that increased over four years. Clinically, a ganglion was suspected on the left midfoot and an MRI showed a heterogeneous lobulated soft tissue mass on the superior aspect of the tarsal midfoot measuring 5.8 x 2.4 x 4.2 cm. The mass causing remodeling and bony erosion was more appreciated at the medial aspect of the talus bone and extended to the sinus tarsi and talocalcaneal joint space. Surgical excision of the mass was performed, and pathology reports found lobulated soft tissue lesions composed of mononuclear cells, multinucleated giant cells, sheets of foamy macrophages, inflammatory cells, and hemosiderin-laden macrophages. This case represents D-TGCT without atypia or malignancy based on the findings., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Abed Alharbi et al.)

Tenosynovial giant cell tumor-diffuse type (diffuse TSGCT) is a benign but locally aggressive proliferative disorder of the synovium. Treatment is usually surgical, although in cases of extensive disease complete synovectomy is not possible and local recurrence rates are high. Pexidartinib (trade name Turalio®), a colony-stimulating factor-1 (CSF-1) inhibitor, was shown in a recent phase III trial to effectively treat diffuse TSGCT and is FDA approved for the treatment of adult patients with symptomatic diffuse TSGCT associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Pexidartinib is available only through a restricted program under a risk evaluation and mitigation strategy (REMS) because of the risk of hepatotoxicity. Magnetic resonance imaging (MRI) is the preferred imaging modality for the diagnosis and surveillance of TSGCT. Here we present three patients with diffuse TSGCT of the knee who underwent multiple MRIs over several years while on pexidartinib. We describe the disease burden and signal characteristics on MRI and correlate with the response reported in the patients' medical records. Given that the use of pexidartinib and other CSF inhibitors is likely to increase, musculoskeletal radiologists should be aware of this novel non-operative treatment and the MRI appearance of diffuse TSGCT during therapy. [ABSTRACT FROM AUTHOR]

Objective: Pigmented villonodular synovitis occurring in the region of the temporomandibular joint is a rare disease, requiring a review of the treatment method, follow-up period.Method: Refer to the past literature, along with a retrospective search.Results: An excision, including the skull base bone, was performed in all cases; however, recurrence was found in one case on which fractional excision was performed. Past reports have also indicated that en bloc resection was considered desirable.Conclusion: It is necessary to perform en bloc resection on patients with pigmented villonodular synovitis occurring in the region of the temporomandibular joint. Furthermore, due to reported cases of recurrence after a long period of time, follow-up observations of about 10 years are considered necessary. [ABSTRACT FROM AUTHOR]

Desmoplastic fibroblastoma is an uncommon, benign fibrous soft tissue tumor that usually occurs in the arms, shoulders, neck, hands, and feet in the fifth to seventh decades of life. In general, it is commonly located in the subcutaneous tissue and skeletal muscle. The authors report an unusual case of a desmoplastic fibroblastoma mimicking tenosynovial giant cell tumor encasing a tendon of the foot in a 72-year-old woman. Ultrasonography revealed an inhomogeneously hypoechoic lobulated soft tissue lesion completely wrapped around the extensor digitorum longus tendon. Color Doppler study revealed increased vascularity in the internal and peripheral portions of the lesion. Magnetic resonance imaging revealed a well-defined, lobulated soft tissue mass encasing the extensor digitorum longus tendon with predominantly isointense signal with some areas of hypointense signal on T1-weighted images, predominantly hyperintense signal with some areas of hypointense signal on T2-weighted images, and inhomogeneous enhancement on fat-suppressed contrast-enhanced T1-weighted images. Surgical excision was performed, and the mass was diagnosed on pathological examination as a desmoplastic fibroblastoma. There has been no previously published radiologic case of a desmoplastic fibroblastoma encasing a tendon of the foot in the literature. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The aim of this study is to bring attention to a unique occurrence in an uncommon location and to describe our approach to treatment in this context. We describe a case of a 36-year-old male who presented with complaints of pain in his left knee for three months, with a restricted range of motion, without a prior history of trauma. A thorough knee examination was performed, which was unremarkable except for a restricted range of motion and tenderness along the medial joint line. A plain radiograph of the knee revealed no bony injury. MRI was done to assess the extension and it confirmed a soft tissue mass beneath the patella. The patient was taken up for surgery after a pre-anesthetic checkup and the mass was removed arthroscopically in toto using a higher accessory antero-medial portal. The mass was removed with the help of a spatula without damaging it and sent for histopathological analysis. Histopathology confirmed that it was a giant cell tumour of the tendon sheath. The procedure was uneventful, and the patient achieved a full range of motion post-operatively., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Deshmukh et al.)

A giant cell tumor of the tendon sheath (GCTTS) presents as a rare neoplasm demanding a heightened index of suspicion for precise diagnostic evaluation, especially when manifesting in the digital phalanges, as it is part of a group of neoplasms known as tenosynovial giant cell tumors (TCGTs). An accurate and timely diagnosis is crucial, as it significantly enhances treatment outcomes for this heterogeneous group of lesions. We describe the case of a male patient who presented with multiple nodules in the fourth finger of his left hand and was ultimately diagnosed with a localized form of a GCTTS, an unusual presentation for localized forms of this entity. Our objective is to outline the diagnostic and therapeutic approach, discussing options for differential diagnosis and treatment modalities. To achieve this, we conducted a literature review and compared our findings and the observed evolution in our patient. Early recognition of hand tumors allows for timely diagnosis, facilitating optimal resections during surgical procedures. This, in turn, reduces morbidity and enhances the functionality of the affected extremity, as detailed in the current case., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Meza-Martinez et al.)

Introduction: Giant cell tumor of tendon sheath (GCTTS), also known as tenosynovial giant cell tumor or pigmented villonodular tenosynovitis, is a rare benign soft-tissue tumor with an unclear cause. It is the second most frequent soft-tissue tumor in the hand after ganglion cyst., Case Report: We described a female patient, age 19, who has had a 3 cm × 2 cm firm swelling on the palmer aspect of the right second metacarpal region for 7 years. The bulge developed spontaneously and moved quite slowly. It is required to do a histological and radiographic evaluation to determine whether or not to pursue additional treatment. Excision surgery was done, and the tumor was entirely removed. According to histopathology, this mass was compatible with GCTTS without being malignant., Conclusion: It is an uncommon instance of GCTTS at the hand, to sum up. The tumor should be entirely excised due to its high risk of recurrence to lower the likelihood of recurrence and restore hand function., Competing Interests: Conflict of Interest: Nil, (Copyright: © Indian Orthopaedic Research Group.)

Background: Although tenosynovial giant cell tumor (TGCT) is classified as a benign tumor, it may undergo malignant transformation and metastasize in extremely rare occasions. High aberrant expression of CSF1 has been implicated in the development of TGCT and recent studies have shown promising activity of several CSF1R inhibitors against benign diffuse-type TGCT; however, little is known about their effects in malignant TGCT.Case Presentation: Information from six consenting patients (3 men, 3 women) with malignant TGCT presenting to Dana-Farber Cancer Institute for initial or subsequent consultation was collected. Median age at initial diagnosis of TGCT was 49.5 years (range 12-55), and median age at diagnosis of malignant TGCT was 50 years (range 34-55). Two patients developed malignant TGCT de novo, while four other cases showed metachronous malignant transformation. All tumors arose in the lower extremities (3 knee, 2 thigh, 1 hip). Five patients underwent surgery for the primary tumors, and four developed local recurrence. All six patients developed lung metastases, and four of five evaluable tumors developed inguinal and pelvic lymph node metastases. All six patients received systemic therapy. Five patients were treated with at least one tyrosine kinase inhibitor with inhibitory activity against CSF1R; however, only one patient showed clinical benefit (SD or PR). Five patients were treated with conventional cytotoxic agents. Doxorubicin-based treatment showed clinical benefit in all four evaluable patients, and gemcitabine/docetaxel showed clinical benefit in two patients. All six patients died of disease after a median of 21.5 months from diagnosis of malignant TGCT.Conclusions: This study confirms that TGCT may transform into an aggressive malignant tumor. Lymph node and pulmonary metastases are common. Local recurrence rates are exceedingly high. Conventional cytotoxic chemotherapy showed clinical benefit, whereas tyrosine kinase inhibitors against CSF1R showed limited activity. Given its rarity, a prospective registry of malignant TGCT patients is needed to further understand the entity and to develop effective strategies for systemic treatment. [ABSTRACT FROM AUTHOR]

Purpose: Pigmented villonodular synovitis (PVNS)/tenosynovial giant cell tumor (TGCT) is a benign, proliferative lesion of the synovium, the bursa, and the tendon sheath. Little is known about the anatomical distribution pattern of diffuse extra-articular PVNS/TGCT around the knee joint. In this retrospective study, anatomical distribution of PVNS/TGCT using magnetic resonance imaging (MRI) and arthroscopy was analyzed.Methods: This study was designed as a retrospective, observational cross-sectional study based on MRI and arthroscopy. Twenty-four PVNS/TGCT patients (24 knees) who underwent arthroscopic or posterior open surgery between 2009 and 2016 were enrolled. Of these, eight intra-articular and 16 diffuse extra-articular PVNS/TGCT of the knee were classified. The anatomical locations of the PVNS/TGCT masses were determined with a newly devised mapping scheme. Analysis was performed on the prevalence of each compartment and agreement rates between each compartment.Results: The point prevalence of intra-articular posterior compartment was higher in diffuse extra-articular PVNS/TGCT group compared with intra-articular PVNS/TGCT group. The point prevalence of diffuse PVNS/TGCT was most prevalent in the extra-articular posterolateral compartment (12 out of 16 diffuse extra-articular PVNS/TGCT patients, 75%) and second most common in the below to joint capsule compartment (11 out of 16, 68.8%). The agreement rate was the highest between intra-articular posterolateral and extra-articular posterolateral compartments (75%).Conclusion: Extra-articular invasion of diffuse PVNS/TGCT occurred in specific patterns in the knee joint. Extra-articular lesions were always accompanied by lesions in intra-articular compartments. In particular, lesions in the intra-articular posterior compartments were observed in all of the diffuse extra-articular PVNS/TGCT patients. The point prevalence of diffuse extra-articular PVNS/TGCT for each compartment was the highest [12 out of 16 (75%)] in extra-articular posterolateral compartment. In contrast, invasion to the extra-articular posteromedial side was less frequent [5 out of 16 (31.3%)] than to the extra-articular posterolateral side. Knowing where the lesions frequently occur may provide important information for deciding the timing, method, and extent of surgery.Level Of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Pigmented villonodular synovitis (PVNS) is a benign disease that rarely undergoes malignant transformation. Th ere are two types of disease: localized (nodular tenosynovitis) and diff used (pigmented villonodular synovitis/tenosynovitis) with intra- or extra-articular locations. The second one is limited to synovium of the burse (PVNB) or tendon sheath (PVNTS). The intraarticular lesions are usually located in the knee, hip, ankle and elbow joints. Histologically, PVNS is a tenosynovial giant cell tumor, characterized by proliferation of two types of mononuclear cells -- predominantly small, histiocyte-like cells and larger cells with dense cytoplasm, reniform or lobulated nucleus, with accompanying multinucleated giant cells and macrophages overloaded with hemosiderin that give typical image on MRI -- currently selected as a gold standard for its diagnosis. The classic X-ray and CT are non-specific but similar to ultrasound should be used to evaluate disease progression and treatment response if radiotherapeutic and pharmacological methods were selected for treatment. An open arthroscopic surgery could also be applied in selected cases. [ABSTRACT FROM AUTHOR]

Giant cell rich lesions of the temporal bone encompass a wide spectrum of disease that includes infectious, reactive, and neoplastic processes. When dealing with any lesion that can potentially involve bone, it is important to understand both the clinical presentation and to correlate the histologic findings with the radiologic imaging. This review discusses the clinical, the pathologic features including the differential diagnosis, and the treatment of some of the more commonly encountered giant cell rich entities in this region. [ABSTRACT FROM AUTHOR]

Purpose: Tenosynovial giant cell tumor of the diffuse type (TGCT-D) involving the spine is rare. Its differential diagnosis includes metastatic disease; however, there have been few reports of spinal TGCT-D mimicking spinal metastasis in patients with a history of malignancy.Methods: We report on a 35-year-old woman with a history of papillary thyroid cancer who was diagnosed with TGCT-D of the thoracic spine mimicking spinal metastasis. Preoperative computed tomography (CT) revealed a 1.0 × 1.0-cm lytic bone lesion involving the left T7 vertebral lamina, pedicle, and the T6-7 facet joint; the thoracic spine lesion was markedly fluorodeoxyglucose-avid on positron-emission tomography/computed tomography (PET/CT).Results: Spinal metastasis was initially suspected given the patient's history of papillary thyroid cancer. Total excision was performed with recapping laminoplasty. The resected lamina was frozen in liquid nitrogen and used as a frozen autograft (frozen recapping laminoplasty) for spinal reconstruction with posterior instrumentation. Histological findings supported a diagnosis of TGCT-D. The patient had no evidence of local recurrence 2 years post-surgery. Bone union was achieved 3 years post-surgery.Conclusions: TGCT-D can mimic metastasis in PET/CT and should be included in the differential diagnosis if a lytic lesion affecting the posterior elements of the vertebrae involves the facet joints. CT-guided biopsy is recommended for accurate diagnosis when an occult tumor, such as TGCT, is incidentally detected on PET-CT, even in patients with a history of malignant neoplasm. Frozen recapping laminoplasty is useful for complete resection of a spinal tumor, preventing local recurrence, and preservation of the posterior spinal elements. [ABSTRACT FROM AUTHOR]

Objectives: To elucidate the clinical behavior, treatment, and outcomes of tenosynovial giant cell tumors (TGCT) involving the temporomandibular joint (TMJ) and adjacent temporal bone.Study Design: Retrospective case series with histopathologic review.Methods: A retrospective chart review was performed identifying and collecting data from all cases of TGCT involving the TMJ and adjacent temporal bone that were treated at the authors' center between January 1960 and December 2015.Results: Eleven histopathologically confirmed cases met inclusion criteria. The median age at diagnosis was 49 years, eight patients were men, and the median follow-up was 116 months. Computed tomographic (CT) imaging revealed a lytic expansile mass centered on the TMJ. Magnetic resonance imaging (MRI) most commonly exhibited hypointense signal on precontrast T1- and T2-weighted sequences and variable postcontrast enhancement. The median delay in diagnosis was 24 months, and the most common presenting symptoms were hearing loss and pain. All patients underwent surgical resection, eight receiving gross total removal, one receiving near total removal, and two patients from early in the series receiving subtotal resection with neoadjuvant or adjuvant radiation. Histopathological review of surgical specimens revealed chondroid metaplasia in seven tumors. Eight of nine cases receiving gross total or near total resection have no evidence of recurrence to date.Conclusions: TGCT of the TMJ and temporal bone are rare and locally aggressive tumors that commonly present with nonspecific symptoms. A careful review of CT and MRI followed by early biopsy is critical in establishing an accurate diagnosis and facilitating appropriate treatment. TGCT of the TMJ more commonly contain chondroid metaplasia when compared to TGCT at other anatomic locations. Gross total resection is achievable in most cases and offers long-term cure. Radiation may be considered for recurrent disease or adjuvant therapy following subtotal resection.Level Of Evidence: 4. Laryngoscope, 127:2340-2346, 2017. [ABSTRACT FROM AUTHOR]

Background: Tenosynovial giant cell tumor (TGCT) is a relatively rare disease often misdiagnosed as osteoarthritis. Synovectomy or arthroplasty is the recommended treatment option, but recurrence is common after surgery. This study aimed to determine the prognosis of patients with advanced TGCT that was diagnosed incidentally during total knee arthroplasty (TKA) for osteoarthritis and treated by synovectomy.Methods: From January 2008 to July 2011, TGCT was diagnosed incidentally in 10 patients (a total of 11 individual knees) undergoing posterior-stabilized TKA for an initial diagnosis of osteoarthritis. TGCT was confirmed by histopathology of biopsy specimens. Partial synovectomy was performed for localized-type TGCT (3 knees, 3 patients) and total synovectomy for diffuse-type TGCT (8 knees, 7 patients).Results: All patients were female with a mean age of 61.7 ± 6.6 (range 50-70) years. No postoperative infection, nerve injury, or deep venous thrombosis occurred. All patients were followed up for a mean period of 60.9 ± 6.6 (39-83) months, and no recurrence of TGCT occurred. X-ray imaging showed no apparent radiolucent lines around the prosthesis, and no prosthetic loosening, subsidence, or osteolysis. The joints were stable, with a significantly improved range of motion following surgery (109.5° ± 8.8° vs 80.5° ± 16.8°, P < .01). The Knee Society scores for knee joint (90.0 ± 4.1 vs 40.5 ± 8.1) and knee function (81.8 ± 7.5 vs 35.0 ± 13.8) were both significantly improved after surgery (P < .01).Conclusion: Inactive TGCT could not be diagnosed preoperatively. TKA combined with synovectomy is effective in the treatment of advanced TGCT with degenerative lesions. [ABSTRACT FROM AUTHOR]

Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions. [ABSTRACT FROM AUTHOR]

Tenosynovial giant cell tumor (TGCT) is a rare, benign, locally aggressive synovial based neoplastic process that can result in functional debilitation and end-stage arthrtitis. Although surgical resection is the primary treatment modality, novel systemic therapies are emerging as part of the multimodal armamentarium for patients with unresectable or complex disease burden. This review discusses the pathogenesis of TGCT, potential druggable targets and therapeutic approaches. It also evaluates the safety and efficacy of different systemic therapies., (© 2023 The Authors. Journal of Surgical Oncology published by Wiley Periodicals LLC.)

Background: Arthroscopic resection of tenosynovial giant cell tumor (TS-GCT) presents favorable outcomes. However, there are reportedly higher recurrence rates in patients who had incomplete resection. To minimize incomplete resection, we established a multiple portal approach depending on the location of the disease. In this study, we aimed to retrospectively evaluate the clinical outcomes of arthroscopic resection for both localized and diffuse types of TS-GCT of the knee., Methods: From 2009 to 2019, 13 patients who underwent arthroscopic synovectomy of the knee and were histologically diagnosed with TS-GCT were included in this study. The pre- and postoperative range of motion (ROM) of the knee was measured. The Japanese Orthopaedic Association (JOA) score and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were assessed at the final follow-up examination. Magnetic resonance imaging was performed to detect incomplete resection or local recurrence., Results: Among the 13 patients, seven and six had localized and diffuse type TS-GCT, respectively. Regarding the knee ROM, preoperative knee flexion in patients with the localized type was limited compared with that in those with the diffuse type. However, the ROM was significantly improved in patients with both types postoperatively. The JOA score and KOOS of patients with both types at the final follow-up were favorable, and there were no significant differences between both types. There was neither recurrence nor incomplete resection in any patient for both types., Conclusion: All patients, regardless of the TS-GCT type, achieved favorable outcomes after arthroscopic surgery; especially, the failure rate was 0%., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Tenosynovial giant cell tumor (TGCT) occurs most commonly in the appendicular skeleton and is only rarely found in the vertebral column. Lesions of the craniocervical junction are particularly rare, with only 4 cases reported in the literature. The authors describe the case of a diffuse-type TGCT at the craniocervical junction., Observations: A patient presented with a 1-year history of right-sided neck pain and bilateral neurological symptoms in the distribution of the right occipital nerve. A 20-mm homogeneously contrast-enhancing mass in the suboccipital and posterior C1 region was discovered on magnetic resonance imaging of the cervical spine. The tumor was operated on via a posterior approach, and gross-total resection (GTR) was achieved. Immunohistochemical (IHC) examination revealed a diffuse-type TGCT. The patient had an uneventful recovery., Lessons: TGCT can arise at the craniocervical junction and is easily misdiagnosed because of its rare occurrence. IHC examination of a tumor specimen should be done to confirm the diagnosis. GTR is the objective when treating these tumors, especially when they are the diffuse type, as they have a high recurrence rate. Radiation and small-molecule therapies are viable postoperative therapies if GTR cannot be achieved or in cases of recurrence.

Diffuse-type tenosynovial giant cell tumor can rarely present as an entirely extra-articular mass, which can be misdiagnosed as a sarcoma especially when giant cells are absent, dominated by large dendritic mononuclear cells, and desmin expression is extensive. [ABSTRACT FROM AUTHOR]

Arka çapraz bağdan köken alan tenosinovyal dev hücreli tümör

Objectives: Temporal tenosynovial giant cell tumors (TGCTs) are often large and have invaded the middle skull base. It is difficult to protect the important neurovascular structures around the tumor and perform functional reconstruction on the basis of complete tumor resection. This study aimed at analyzing the surgical techniques and functional reconstruction during the operation of complex TGCT of temporal bone and middle skull base. Methods: Five patients with pathologically confirmed TGCT of different complex types in the temporal bone and middle skull base were treated in our hospital from December 2020 to February 2023. We collected and retrospectively analyzed their medical records, including medical imaging, surgical procedures, and follow-up data. Results: The tumors invaded beyond the temporal bone and destroyed the middle skull base in all cases, involving the intracranial space and other important neurovascular structures. The internal carotid artery, infratemporal fossa, pterygopalatine fossa, and parapharyngeal space were also involved in 1 case. All the patients' tumors were completely removed, and the operations were performed mainly via modified infratemporal fossa approach, or combined with expanded middle cranial fossa approach. All cases with temporal and skull base destruction were repaired using the temporalis muscle flap with no occurrence of intracranial complications. The dura mater, condyle of temporomandibular joint, facial nerve, and internal carotid artery were fully preserved. Normal maxillofacial morphology was also preserved. The air conductive hearing of 2 patients was preserved. Conclusions: We found and summarized some surgical techniques that can help safeguard the important structures around massive TGCTs of temporal bone and middle skull base, and reconstruct the defects after tumor resection. The techniques are effective and feasible., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: To investigate the clinical characteristics and surgical efficacy of localized tenosynovial giant cell tumors in children., Methods: The clinical data, surgery, and follow-up results of 17 children with localized tenosynovial giant cell tumors who visited our hospital from 2011 to 2021 were collected for statistical analysis., Results: The median patient age was 7 years and 8 months, and the ratio of males to females was 1.43 (10/7). The predilection of disease was similar in hands and feet, and the common presenting symptom was mass. One patient experienced recurrence after surgery, and one child had postoperative functional limitations., Conclusion: Extremities are common sites of localized tenosynovial giant cell tumors in children. Complete surgical resection helps reduce the recurrence rate., Level of Evidence: Level III., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Giant cell tumor of the tendon sheath (GCTTS) is a common mass in the digits, hands, and upper extremities. Diagnosis is made on clinical examination, adjunctive imaging, and distinct intraoperative findings. Surgical excision is the mainstay of treatment. GCTTS are typically found on flexor surfaces with the dorsal distal thumb being an unusual location. Any surgical approach to the digit should balance oncologic margins with preserving function. GCTTS have a tendency to recur and should be approached in a methodical manner with risk factors of recurrence in mind. This case report reviews the history of GCTTS, surgical approaches to the digit, and risk factors for recurrence to achieve success in the surgical management of these tumors., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Brummund et al.)

Purpose: Tenosynovial giant cell tumors (TSGCTs) are benign but aggressive lesions, and the treatment is resection. A low to intermediate signal intensity on both T1- and T2-weighted images of magnetic resonance imaging (MRI) is characteristic, which is similar to the signal intensity of muscle, and therefore can be challenging for lesion detection. T2-star (T2*)-weighted MR images reflect paramagnetic deoxyhemoglobin, methemoglobin, or hemosiderin., Methods: In 23 TSGCT patients (6 male and 17 females), the T2*MRI findings were analyzed. The tumor locations involved 10 large joints including nine knees and one ankle, 10 small joints including six fingers and four toes, as well as three wrists/hands., Results: Ten diffuse and 13 localized tumors were predominantly located in the large joints and small joints, respectively. The T2*-weighted images indicated three signal patterns of low, iso and high signal intensity compared to muscle. Low-, iso- and high-signal intensities were seen in 22 (96 %), 23 (100 %) and 12 (52 %) of the locations, respectively. To distinguish TSGCTs from the surrounding tissue, the low intensity T2*-weighted images and low to intermediate intensity T1-weighted images when compared to muscle and fluid, respectively were useful for the large joints. Low to intermediate intensity on T1- or T2-weighted images was useful to distinguish TSGCTs from subcutaneous tissue in the small joints., Conclusions: MRI using T2*-, as well as T1- and T2-weighted images, may be useful to detect lesions and assess the extent of TSGCTs in a tissue-specific manner, which is important for surgical planning., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Giant cell tumor (GCT) of tendon sheath is a localized form of tenosynovial GCT, which preferentially affects the joints of hands and feet. Chondroid metaplasia is a rare phenomenon in tenosynovial GCT either in localized or diffuse types. The current case investigates the cytological and histopathological features of chondroid GCT of tendon sheath in a 22-year-old female presenting with wrist swelling.

Sarcoidosis is a systemic inflammatory disorder characterized by non-caseating granulomas, predominantly involving lung, mediastinal lymph nodes and other organs. Synovium involvement is infrequent, and as far as we know, involvement of a periprosthetic membrane has not been reported in the English literature. Intra-articular diffuse tenosynovial giant cell tumor ("conventional diffuse pigmented villonodular synovitis") is an uncommon, locally aggressive neoplasm with few previous case reports in which it arose in periprosthetic tissues after knee arthroplasty. We describe a unique case of an intraarticular mass next to a total knee prosthesis implanted 6 years ago in a patient with a history of pulmonary sarcoidosis. Clinically, this 67-year-old gentleman presented with progressive left knee pain, effusion and marked instability. MRI showed a large complex effusion with synovial thickening in the supra patella recess and the medial and lateral gutters. In addition, a large multilobulated mass with mixed low and high signal intensity was present in the posterior joint space, extending into the popliteal area. A two-stage operation was performed. Histologically, the mass from the posterior joint space showed characteristic features of diffuse tenosynovial giant cell tumor, while the synovium from the anterior compartment demonstrated sarcoidal granulomatous inflammation. Orthopaedic wear debris was found within the giant cells of these sarcoidal granulomata. The histologic features are different from those "usual" macrophage reactions to the particles of debris. In this article, we also included two optional links (highlighted in blue in the figures) to digital whole slide image (WSI), which allow the readers to navigate the entire microscope slides. [ABSTRACT FROM AUTHOR]

Background: A tenosynovial giant cell tumor (T-GCT) is a benign synovial tumor arising from the synovium, bursae, or tendon sheath. It can be intra- or extra-articular and localized or diffuse. Diffuse T-GCT is considered as a locally aggressive. Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose with computed tomography (FDG PET/CT) is widely used to differentiate malignant from benign tumors and to detect distant metastasis. However, FDG PET/CT is limited by false-positive findings. In this study, we present two cases of T-GCT that developed in unusual locations and were confused with malignant tumors. The final diagnoses were histologically confirmed as T-GCTs.Case Presentation: Case 1. A 45-year-old Japanese female presented with a left choroidal melanoma and an abnormal lesion adjacent to the first cervical (C1) lamina confirmed by a PET scan (maximum standardized uptake value [SUVmax] =9.9 g/ml). MRI of the neck also detected a soft tissue mass (14.6 × 7.7 × 7 mm) adjacent to the C1 lamina. The choroidal melanoma was treated by heavy carbon ion radiotherapy. Although the size of the C1 soft tissue tumor remained unchanged, a CT-guided biopsy confirmed the diagnosis of the neck mass as a T-GCT. Case 2. A 15-year-old Japanese male with multiple type 1 neurofibromatosis presented with a soft tissue mass (26.1 × 24.7 × 11.5 mm) of the extra-articular hip joint that was coincidentally detected by FDG PET/CT during examination of a mediastinal soft tissue mass. SUVmax of the mediastinal lesion was 2.6 g/ml and of the hip lesion was 12.8 g/ml. Thus, differentiation from a malignant tumor, such as a malignant peripheral nerve sheath tumor, was necessary. An open biopsy was performed, and the frozen section was diagnosed as T-GCT. The tumor was excised, and the final histological diagnosis confirmed T-GCT.Conclusion: T-GCT can show high FDG uptake, which might be confused with malignancy. Although MRI findings and location might help in the diagnosis of a T-GCT, careful assessment is mandatory, especially in unusual locations. [ABSTRACT FROM AUTHOR]

Tenosynovial giant cell tumors (TGCT) are rare benign soft tissue tumors affecting mostly young adults. The most common affected sites include the knee, ankle, elbow, shoulder, and fingers. The temporomandibular joint is occasionally affected. Herein, we report a case of a 31-year-old Caucasian male who presented clinically with a parotid gland mass. The initial clinical and radiological work-up failed to reveal any involvement of the adjacent temporomandibular joint. Fine-needle aspiration revealed a cellular tumor composed of mononuclear and multinucleated giant cells with fibrosis and hemosiderin deposition. This was subsequently found to be a TGCT arising from the temporomandibular joint. Giant cell-rich lesions are uncommon in salivary glands. Herein, we describe the cytomorphology and clinico-radiographic features of this tumor with emphasis on the differential diagnosis of giant cell-rich lesions presenting in salivary glands. Despite its rare occurrence, this entity should be considered when giant cells are prominent in specimens acquired from this location.

Tenosynovial giant cell tumor (TGCT), a benign proliferative lesion arising from the synovial membrane of the joints, is rarely seen in the temporomandibular joint. It frequently presents as a painful, preauricular swelling and affects the jaw functions. Two types of TGCT seen are diffuse TGCT (TGCT‑D) and localized TGCT. A case of TGCT‑D is described here, the highlight of the case being extensive areas of chondroid metaplasia which mimicked chondroid lesions, but was ruled out based on negative immunohistochemical findings within the tumor cells. [ABSTRACT FROM AUTHOR]