[Diagnosis and management of tenosynovial giant cell tumor]. / Diagnostic et prise en charge de la tumeur à cellules géantes ténosynoviale.

Tenosynovial giant cell tumor is a benign condition that originates from synovial cells within joints, tendon sheaths, or bursae and may present either in localized (benign) or diffuse (locally aggressive) forms. Currently, the primary treatment approach is surgical, yielding satisfactory results with low recurrence rates in the localized forms, whereas the diffuse type displays high recurrence rates. In parallel, clinical trials are underway to explore pharmaceutical treatment options for the advanced diffuse type. This article aims at consolidating current knowledge about diagnosis and management of this rare tumor, additionally proposing a brief overview of novel therapeutic approaches.

La tumeur à cellules géantes ténosynoviale, bénigne, prend son origine dans les cellules synoviales des articulations, des gaines tendineuses ou des bourses et se présente dans une forme soit localisée (bénigne), soit diffuse (localement agressive). Le traitement principal est chirurgical, offrant des résultats satisfaisants à long terme, avec un faible risque de récidive dans la forme localisée, alors que le taux de récidives est élevé dans la forme diffuse. Parallèlement, des essais cliniques sont en cours pour explorer des options de traitement systémique pour les formes diffuses sévères. Cet article rappelle les connaissances actuelles pour le diagnostic et la prise en charge de cette tumeur rare. De plus, nous proposons un aperçu succinct des nouvelles approches thérapeutiques.

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).

Tenosynovial giant cell tumour of the finger: a case report.

Giant cell tumour most commonly occuring in epiphysis of the long bone, present and with pain, tenderness and swelling. It is a solitary lesion with restricted movement and tenderness over the lesion. The tendon sheath is where tenosynovial giant cell tumours typically develop. Because of its remarkably peculiar position, we present a case of giant cell tumour (GCT) tenosynovial of bone in the middle phalaynx in a 33-year-old female with complaints of swelling, pain in ring finger of left hand since 2 months which is rarely seen. After clinical, radiological, pathological investigations tenosynovial giant cell tumour was diagnosed. Following fine needle aspiration cytology, histopathology was utilized to confirm the tumour's diagnosis which was later treated as resection of excision of the tumour with allo/autograft reconstruction. Our case report showed no evidence of recurrence in 2 years of follow-up. Hence our case report proves that early and complete resection of the tumour shows evidence of regain of complete range of motion and decrease recurrence rate.

18F-FDG PET/CT image of tenosynovial giant cell tumor in the thoracic vertebra.

Diffuse-type tenosynovial giant cell tumor (D-TSGCT) is a destructive benign tumor-like proliferative disease. Diffuse-type tenosynovial giant cell tumorrarely arises from the axial skeleton. We report a case of image findings of D-TSGCT in the thoracic vertebra. On fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) image, it presented a lytic bone destruction of 6th thoracic vertebra, vertebral processes as well as adjacent sixth rib with intense 18F-FDG uptake. Our case hints another unusual D-TSGCT image characteristic, which should be considered as a differential diagnosis when we interpret similar sign on 18F-FDG PET/CT.

Giant cell tumor of tendon sheath: A report of 216 cases.

BACKGROUND: In this article on giant cell tumor of tendon sheath (GCTTS), we intend to summarize and analyze the clinical and pathological features of GCTTS hoping to improve clinical management and patient treatment. METHODS: The study retrospectively reviewed 216 patients of GCTTS, registered at the Affiliated Hospital of Southwest Medical University from January 2010 to December 2020. These cases were diagnosed by surgical excision. The clinicopathological features and the prognosis were reviewed in the light of the current literature. RESULTS: Of these 216 GCTTS patients, 72 were males (33.3%) and 144 females (66.7%), with a ratio male-to-female of 1:2. The patients' age ranged from 5 to 82, the average being 41.5 years at diagnosis. A total of 96 cases (44.4%) occurred in the hand region, followed by 35 cases (16.2%) in the knee, 32 cases (14.8%) in the foot, 25 cases (11.6%) in the ankle, 12 cases (5.6%) in the wrist, 12 cases (5.6%) in the leg, 2 cases (0.9%) in the head, 1 case (0.5%) in the forearm, and 1 case (0.5%) inside and outside the spinal channel. Histopathology mainly revealed large synovial-like monocytes, small monocytes, and osteoclast-like giant cells. CONCLUSION: Our results confirm that GCTTS predominantly occurs in the hands of young women. Complete surgical resection with long-term follow-up is the preferred management.

Distraction arthroplasty combined with autologous bone grafting for diffuse-type tenosynovial giant cell tumour with articular cartilage defect and subchondral bone cysts: A case report.

Tenosynovial giant cell tumour (TGCT) encompasses a group of lesions that present with synovial differentiation and most commonly occur in the joint synovium, bursae, and tendon sheaths. Diffuse-type TGCT (Dt-TGCT), previously known as pigmented villonodular synovitis, is one of the most common benign soft-tissue tumours of the foot and ankle and usually affects young adults. The differential diagnosis of Dt-TGCTs remains a clinical problem because their clinical symptoms are similar to those of inflammatory arthritis, including rheumatoid arthritis. Moreover, persistent Dt-TGCTs can lead to articular deterioration, including osseous erosions and subchondral bone cysts. Joint-preserving procedures are considered optimal for treating younger patients with ankle osteoarthritis because the indication of ankle arthrodesis and total ankle arthroplasty is limited. Thus, ankle distraction arthroplasty could be an alternative for treating Dt-TGCT with articular deterioration in young patients. Here, we report about a woman in her early 30s who presented with ankle pain owing to a Dt-TGCT with an articular cartilage defect and subchondral bone cysts. We performed ankle distraction arthroplasty combined with an autologous bone graft. A follow-up examination at 2 years revealed preservation of physical function and pain alleviation. These findings suggest that distraction arthroplasty is a viable treatment option for remedying the destruction of the articular cartilage and subchondral bone owing to Dt-TGCTs in young adults.

Diagnostic utility of CSF1 immunohistochemistry in tenosynovial giant cell tumor for differentiating from giant cell-rich tumors and tumor-like lesions of bone and soft tissue.

BACKGROUND: Tenosynovial giant cell tumor (TSGCT) is a benign fibrohistiocytic tumor that affects the synovium of joints, bursa, and tendon sheaths and is categorized into localized TSGCT (LTSGCT) and diffuse TSGCT (DTSGCT). LTSGCT and DTSGCT are characterized by recurrent fusions involving the colony-stimulating factor 1 (CSF1) gene and its translocation partner collagen type VI alpha 3 chain. The fusion gene induces intratumoral overexpression of CSF1 mRNA and CSF1 protein. CSF1 expression is a characteristic finding of TSGCT and detection of CSF1 mRNA and CSF1 protein may be useful for the pathological diagnosis. Although there have been no effective anti-CSF1 antibodies to date, in situ hybridization (ISH) for CSF1 mRNA has been performed to detect CSF1 expression in TSGCT. We performed CSF1 immunohistochemistry (IHC) using anti-CSF1 antibody (clone 2D10) in cases of TSGCT, giant cell-rich tumor (GCRT), and GCRT-like lesion and verified its utility for the pathological diagnosis of TSGCT. METHODS: We performed CSF1 IHC in 110 cases including 44 LTSGCTs, 20 DTSGCTs, 1 malignant TSGCT (MTSGCT), 10 giant cell tumors of bone, 2 giant cell reparative granulomas, 3 aneurysmal bone cysts, 10 undifferentiated pleomorphic sarcomas, 10 leiomyosarcomas, and 10 myxofibrosarcomas. We performed fluorescence ISH (FISH) for CSF1 rearrangement to confirm CSF1 expression on IHC in TSGCTs. We considered the specimens to have CSF1 rearrangement if a split signal was observed in greater than 2% of the tumor cells. RESULTS: Overall, 50 of 65 TSGCT cases, including 35 of the 44 LTSGCTs and 15 of the 20 DTSGCTs, showed distinct scattered expression of CSF1 in the majority of mononuclear tumor cells. MTSGCT showed no CSF1 expression. Non-TSGCT cases were negative for CSF1. FISH revealed CSF1 rearrangement in 6 of 7 CSF1-positive cases on IHC. On the other hand, FISH detected no CSF1 rearrangement in all CSF1-negative cases on IHC. Thus, the results of IHC corresponded to those of FISH. CONCLUSION: We revealed characteristic CSF1 expression on IHC in cases of TSGCT, whereas the cases of non-TSGCT exhibited no CSF1 expression. CSF1 IHC may be useful for differentiating TSGCTs from histologically mimicking GCRTs and GCRT-like lesions.

t(1;2)-Positive Localized Tenosynovial Giant Cell Tumor With Bone Invasion.

BACKGROUND: Localized tenosynovial giant cell tumor (LTGCT) is one of the most common benign soft-tissue tumors of the foot. Although pressure erosion in the adjacent bone may be seen, intraosseous invasion of LTGCT is extremely rare. Recent molecular studies have identified the presence of pathognomonic translocation involving the colony stimulating factor 1 (CSF1) gene at 1p13. CASE REPORT: We present an unusual case of LTGCT mimicking a malignant tumor on imaging. The patient was a 16-year-old woman with no history of trauma who presented with a 2-year history of a slow-growing, painless mass in the left fourth toe. Physical examination revealed a 2-cm, elastic hard, immobile, nontender mass. Plain radiograph showed a lytic lesion with a partially sclerotic rim in the proximal phalanx of the fourth toe. Computed tomography demonstrated an expansile lesion with plantar cortical destruction. Magnetic resonance imaging revealed a nodular mass with intermediate signal intensity on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. The mass had intense contrast enhancement. Complete excision of the mass was performed, and the bone defect was repaired with calcium phosphate cement. Cytogenetic analysis revealed a t(1;2)(p13;q37) translocation as the sole anomaly. Fluorescence in situ hybridization demonstrated the presence of CSF1 rearrangements. CONCLUSION: Although extremely rare, LTGCT should be considered in the differential diagnosis of an intraosseous lesion near small joints, especially when seen in the toe.

[MULTIPLE GIANT CELL TUMOR OF TENDON SHEATH: A CASE REPORT OF THREE LESIONS ON THE SAME FLEXOR TENDON].

INTRODUCTION: We present a case report of a triple location Giant Cell Tumor of tendon sheath appearance on the same flexor tendon sheath of a single digit. There have been scarce descriptions of multiple Giant Cell Tumors of tendon sheath. Multiple tumors may predispose patients to a higher recurrence rate; therefore, recognition and treatment of this rare entity is important.

Benign Hand Tumors (Part II): Soft Tissue Tumors.

Background: Benign soft-tissue tumors of the hand are more common than both their benign bone and malignant soft-tissue counterparts. This study evaluates the characteristics and treatment of benign soft tissue tumors in light of 1 institution's experience. Methods: Histologically confirmed benign soft-tissue tumors of the hand were retrospectively identified using International Classification of Disease codes from 1992 to 2015. A medical chart review was conducted to collect patient demographics, tumor epidemiology, and treatment. Results: A total of 199 soft-tissue tumors were identified. The median patient age at time of treatment was 47.4 ± 14.7 years in age. The majority of tumors were located in the digits (n = 168, 84%) and treated by excision (n = 191, 96%). Localized type tenosynovial giant cell tumors (n = 71, 36%) were the most common and had the highest rates of recurrence (8.5%) in this series. Other frequent histologies included hemangioma, schwannoma, and glomus tumors. Conclusion: Awareness and understanding of tumor characteristics may help physicians with diagnosis and treatment. There is an extensive variety of tumors, but the principles of clinical and imaging diagnosis are common to all of them. Marginal excision for the treatment pain, improvement of function, and cosmetic correction applies to all these tumors independent of the histology.

Intramuscular Tenosynovial Giant Cell Tumor Harboring a Novel CSF1-CD96 Fusion Transcript.

Tenosynovial giant cell tumors typically arise in the synovium of joints, bursae, or tendon sheaths. They may occur in an intra- or extra-articular location and can be divided into localized and diffuse types. The neoplastic nature of the lesion has been supported by a recurrent CSF1 gene rearrangement in a small subset of lesional cells, of which the most common fusion partner is COL6A3. Herein, we report a case of intramuscular localized tenosynovial giant cell tumor harboring a novel CSF1-CD96 fusion transcript, thus expanding the molecular profile of this tumor.

Tenosynovial giant cell tumour in Hoffa fat pad: a case report.

Giant cell tumour is a benign lesion classified as a fibrocystic tumour whose localization in Hoffa's fat pad is very rare. Clinical symptoms are insidious and non-specific causing a frequent confusion and delay in diagnosis therefore it should be distinguished radiologically from other similar conditions such as Hoffa´s disease and lipomas. We report a case of a 37-year-old patient, with no relevant history, who complained of a right knee pain for 5 years. Magnetic resonance imaging showed a small nodular mass in Hoffa's pad which was excised through a direct approach. Histologic examination of the specimen revealed a giant cell tenosynovial tumour. One year after surgery, the patient was asymptomatic with no local recurrence. The surgical removal of the tumour is the ideal treatment. The choice between open surgery and endoscopy depends on the site, size, and extent of the tumour.

Similar appearance of different multifocal carpal bone destructing disease entities in 3 patients: A case report.

RATIONALE: Several diseases feature tumors, or tumor-mimicking lesions, that further invade the bone and surrounding joints of the wrist region. Here, we describe 3 rare cases of multiple destructed carpal bones and adjacent joints in different disease entities confirmed via pathologic diagnosis. PATIENT CONCERNS: All 3 cases were examined between January 2016 and December 2019. Three patients presented with similar clinical manifestations and radiographic features, with multiple osteolytic lesions in the carpal bones and metacarpal bone base. DIAGNOSES: The 3 cases were diagnosed as diffuse type tenosynovial giant cell tumor, calcifying aponeurotic fibroma, and rheumatoid arthritis. INTERVENTIONS: Separate, experienced radiologist and pathologist took part in the interpretation and compartmentalization of radiographs and pathological findings, respectively. Even magnetic resonance imaging could not achieve a diagnosis; surgical excision was therefore required, with subsequent pathological assessment for treatment and final diagnosis. OUTCOMES: functional outcomes also differed among patients, poorest in rheumatoid arthritis patient. LESSONS: We report 3 rare disease entities, presenting with multifocal osteolytic lesions in the wrist. They all presented with similar clinical manifestations, and the final diagnoses were made via pathological evaluation. Compared with tenosynovial giant cell tumor and calcifying aponeurotic fibroma, rheumatoid arthritis had the poorest outcome.

RNAscope CSF1 chromogenic in situ hybridization: a potentially useful tool in the differential diagnosis of tenosynovial giant cell tumors.

Colony stimulating factor-1 (CSF1) upregulation and CSF1/colony-stimulating factor 1 receptor (CSF1R) signaling pathway is central to the tumorigenesis of tenosynovial giant cell tumors (TGCT) of both localized (LTGCT) and diffuse (DTGCT) types, and has been demonstrated in a small number of malignant tumors (MTGCT) as well. In situ hybridization for CSF1 mRNA has been shown to be potentially useful in the diagnosis of TGCT, although only a relatively small number of cases have been studied. We studied CSF1 mRNA expression using RNAscope chromogenic in situ hybridization (CISH) in standard tissue sections from 31 TGCT and 26 non-TGCT, and in tumor microarray slides (Pantomics normal MN0341, Pantomics tumor MTU391, Pantomics melanoma MEL961). Among normal tissues, CSF1 mRNA expression was invariably present in synovium (10/10, 100%) and absent in all other normal tissues. All LTGCT and DTGCT were positive (24/24, 100%), exclusively in large, eosinophilic synoviocytes. MTGCT contained large clusters of CSF1-positive malignant synoviocytes (8/8, 100%); malignant spindled cells were also positive. Among non-TGCT, CSF1 CISH was less often positive with high specificity (90%). CSF1-positive cases included leiomyosarcoma, giant cell tumor of bone and of soft parts, pulmonary carcinoma and others. The sensitivity and specificity of RNAscope CSF1 mRNA CISH for the diagnosis of TGCT were 100% and 90%, respectively. We conclude that RNAscope CSF1 CISH may be a valuable adjunct for the diagnosis of TGCT of all types, especially those with atypical or malignant morphologic features. Detection of CSF1 mRNA expression may also have predictive significance in cases where use of the CSF1 inhibitor pexidartinib is considered.

Tenosynovial Giant-Cell Tumor Presenting as Septic Arthritis of the Knee.

Tenosynovial giant-cell tumor (TGCT) is an intraarticular giant-cell tumor of the synovial tissue and tendon sheaths which often mimics multiple conditions on presentation. This case report describes a previously asymptomatic 67-year-old man with preliminary clinical and laboratory evaluation suggestive of septic arthritis; however, arthroscopy revealed diffuse synovitis, and biopsy confirmed TGCT. To our knowledge, this is the first report of TGCT presenting as septic arthritis in an adult patient. This diagnosis should be considered in evaluation of acute, atraumatic knee pain with associated inflammatory marker elevation.

Hand tumors: A review of 186 patients at a single institute.

PURPOSE: The spectrum of diagnoses and clinical features of hand tumors differ from those of tumors in other body parts. However, only a few reports have comprehensively referenced the diagnosis and clinical features of hand tumors. This study aimed to elucidate the diagnostic distribution and the clinical features of hand tumors undergone surgery in our institute. PATIENTS AND METHODS: A total of 235 lesions in 186 patients diagnosed with hand tumors between 1978 and 2020 were reviewed. Age at surgery, gender, chief complaint, tumor location, and pathological diagnosis were analyzed. RESULTS: There were 121 benign bone tumors, 98 benign soft tissue tumors, and 16 malignant tumors. Chondroma and tenosynovial giant cell tumor were common benign bone and soft tissue tumors at the proximal phalanx of the ring finger and the palm, respectively. Meanwhile, chondrosarcoma and synovial sarcoma were common malignant tumors at the dorsal part of the hand. Local pain and painless mass were the chief complaints in patients with benign bone and soft tissue tumors, respectively. Most patients with malignant tumors were referred after unplanned resection. When patients were classified into two categories by tumor size according to maximal diameter, tumors larger than 19 mm had a significantly higher risk of malignant (p = 0.031) despite being smaller than other tumors in different body parts. CONCLUSION: When a tumor malignancy is suspected, the patient should be referred to a specialist to avoid unplanned resection or delayed diagnosis due to misdiagnosis. Knowing the distribution and clinical features should help in diagnosing hand tumors.

Tenosynovial Giant Cell Tumor of the Retropharynx: A Case Report With Literature Review.

Tenosynovial giant cell tumor (TSGCT) represents a family of benign tumors that arise from the synovial tissue of a joint, tendon sheath, or bursa. It usually involves the joints of the extremities and rarely occurs in the head and neck region. Here, we describe a case of a 32-year-old man with a submucosal mass bulging in the posterior pharyngeal wall since one month. The lesion was removed and diagnosed with localized type of TSGCT based on histopathological investigations and clinical presentation. It is very rare that TSGCT occurs in the retropharynx, which reminds clinicians to consider this entity as a possible diagnosis.