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.

Oncological and functional outcomes of modified arthroscopic resection for intra-articular tenosynovial giant cell tumor of the knee using multiple portals.

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%.

[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.

Outcomes of Tenosynovial Giant Cell Tumor of the Foot and Ankle.

BACKGROUND: Tenosynovial giant cell tumor (TGCT) is a benign proliferative disease affecting synovial membranes. There are 2 forms, localized (L-TGCT) and diffuse (D-TGCT), which although histologically similar behave differently. It is locally invasive and is treated in most cases by operative excision. The aim of this study was to assess current practice, how the patients' presentation affected their outcome, as well as review the recurrence rates and complications. METHODS: A retrospective analysis of 123 cases was performed in patients treated between 2003 and 2019 with TGCT of the foot and/or ankle. Data were collected on age at presentation, radiologic pattern of disease, location of disease, treatment provided, and recurrence rates. The minimum follow-up was 2 years with a mean of 7.7 years. RESULTS: There were 61.7% female patients with a mean age of 39 (range, 11-76) years. L-TGCT accounted for 85 (69.1%) cases and D-TGCT for 38 (30.9%). The most prevalent preoperative symptoms were a palpable mass (78/123) and pain (65/123). Radiologically confirmed recurrence in the operative group was noted in 14.5% (16/110) cases. This comprised 4% (3/75) of operatively treated L-TGCT and 37% (13/35) of operatively treated D-TGCT. Patients with pain on presentation and those with erosive changes on presenting magnetic resonance imaging (MRI) were more likely to have persistent postoperative pain (P < .001 for both). Where patients had both preoperative pain and erosive changes, 57.1% had postoperative pain. Thirteen cases were managed nonoperatively where symptoms were minimal, with 1 case requiring surgery at a later date. CONCLUSION: Outcomes of TGCT management are dependent on the disease type, extent of preoperative erosive changes, and presence of preoperative pain. These data are useful for counseling patients regarding the outcomes of surgical intervention and help guide the timing of intervention. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Tenosynovial Giant Cell Tumor (TSGCT) of the hip: MRI accuracy and results of surgical treatment.

Tenosynovial Giant Cell Tumor (TSGCT) or formerly pigmented villonodular synovitis (PVNS) is a rare nonmalignant tumor of the synovia seldom affecting the hip. MRI and surgical resection are the gold standards in its diagnosis and treatment. However, the accuracy of MRI is unknown, and only few reports on its surgical treatment results exist. The goal of the study was to investigate the MRI accuracy, results after surgical treatment, and natural history of untreated MRI-diagnosed hip TSGCT. Twenty-four consecutive patients with suspected TSGCT on hip MRI, between December 2006 and January 2018, were identified from our medical database. Six refused to participate. About 18 patients with a minimal follow-up of 18 months were enrolled. Charts were reviewed for histopathology results, specific treatment and recurrence. At the last follow-up, all patients had a clinical (Harris Hip Score [HHS]) and radiological examination (x-ray and MRI). Out of 18 patients with suspected TSGCT on MRI, with a mean age of 35y (range 17-52), 14 had surgi- cal resection and 4 refused surgery 1 of whom had a CT-guided biopsy. Out of 15 cases with biopsies, in 10 TSGCT was confirmed. Three surgically-treated patients showed recurrence on MRI after 24, 31 and 43 months. Two non-treated patients showed progression after 18 and 116 months. At the last follow-up (65 m; range 18-159), the mean HHS with or without recurrence was 90 and 80pts (ns). Operative vs. non-operative treatment showed HHS of 86 and 90pts (ns). In the conservatively-treated group, HHS with and without progression was 98 and 82pts (ns), respectively. MRI-suspected TSGCT of the hip was confirmed with biopsy in two-thirds of the cases. Surgical treatment showed recurrence in more than one-third of the patients. Two out of four untreated patients showed progression of the TSGCT-suspected lesion.

Arthroscopic resection of localized tenosynovial giant cell tumor in the deep infrapatellar bursa: a case report.

Tenosynovial giant cell tumor (TGCT) is a rare disease characterized by the proliferation of the synovial membrane of a joint, tendon sheath, or bursa. TGCTs in joints are subdivided into the diffuse or localized type. The localized TGCT most frequently affects the knee and may occur in any knee compartment. The most common localization is the Hoffa's fat pad, followed by the suprapatellar pouch and the posterior capsule. Here, we describe a case of a histopathologically proven TGCT of the knee, found in an unusual localization in the deep infrapatellar bursa, which was diagnosed by magnetic resonance imaging. The tumor was entirely arthroscopically resected. The patient had no further complaints following the operation, and there was no recurrence at the 18-month follow-up. Even though TGCT of the knee is uncommon, it should not be overlooked by orthopedic and trauma surgeons, and excision should be regarded as a reliable treatment option. The form of surgical treatment, either open or arthroscopic, should be determined based on a combination of the surgeon's preference and the best approach to the anatomical location of the disease.

Understanding the Effect of Osteoarthritis on Surgical Treatment Patterns, Healthcare Resource Utilization, and Costs Among Patients With Tenosynovial Giant Cell Tumors.

BACKGROUND: Tenosynovial giant cell tumor (TGCT) may be misdiagnosed as osteoarthritis (OA), or the chronic course of TGCT may lead to development of secondary OA. However, little is known about the effect of comorbid OA on long-term surgical patterns and costs among TGCT patients. METHODS: This cohort study used claims data from the Merative MarketScan Research Databases. The study included adults diagnosed with TGCT from January 1, 2014, to June 30, 2019, who have at least 3 years of continuous enrollment before and after the first TGCT diagnosis (date of the first TGCT diagnosis = index date) and no other cancer diagnosis during the study period. Patients were stratified by the presence of an OA diagnosis relative to the index date. Outcomes included surgical procedure patterns, healthcare resource utilization, and costs in the 3-year pre- and postindex periods. Multivariable models were used to assess the effect of OA on the study outcomes, controlling for baseline characteristics. RESULTS: The study included 2856 TGCT patients: 1153 (40%) had no OA before or after index (OA[-/-]), 207 (7%) had OA before index but not after (OA[+/-]), 644 (23%) had OA after index but not before (OA[-/+]), and 852 (30%) had OA before and after index (OA[+/+]). The mean age was 51.6 years, and 61.7% were female. During the postperiod, joint surgery was more common among OA(-/+) and OA(+/+) patients compared with OA(-/-) and OA(+/-) patients (55.7% vs 33.2%). The mean all-cause total costs in the 3-year postperiod were $19,476 per patient per year. Compared with OA(-/-) patients, OA(-/+) and OA(+/+) patients had a higher risk of undergoing recurrent surgery and higher total healthcare costs postindex. DISCUSSION: Higher rates of surgery and increased healthcare cost observed in TGCT patients with postindex OA underscore the need for effective treatment options to reduce joint damage, especially among patients with comorbid OA.

Management of tenosynovial giant cell tumour of the temporomandibular joint: a systematic review.

Diffuse type tenosynovial giant cell tumour of the temporomandibular joint (D-TGCT-TMJ) is a rare proliferative disorder. The aim of this study was to perform a systematic review of the literature to summarize D-TGCT-TMJ management regimes and recurrence rates with at least 12 months of follow-up. Our secondary aim was to propose a minimum period of post-operative follow-up. A medline search for any D-TGCT-TMJ case detailing treatment, follow-up of at least 12 months, and presence of recurrence was undertaken. The following variables were extracted from the studies: patient's age and sex, presence of middle cranial fossa invasion, treatment undertaken, total length of follow-up, and presence of recurrence. All studies were assessed for bias as per the Joanna Briggs Institute systematic reviews appraisal tool. There were 63 cases reviewed and were predominantly managed with total resection (60.3%). Other modalities included: arthroplasty, subtotal resection with or without postoperative radiotherapy, medical therapy and surveillance. The recurrence rate was 9.52% and the longest follow-up period where recurrence was observed was at 60 months. Total resection and arthroplasty are common D-TGCT-TMJ management regimes. Patients with D-TGCT-TMJ should be followed up annually for at least 5 years postoperatively to assess for recurrence.

Tenosynovial Giant Cell Tumor Observational Platform Project (TOPP) Registry: A 2-Year Analysis of Patient-Reported Outcomes and Treatment Strategies.

BACKGROUND: The Tenosynovial giant cell tumor Observational Platform Project (TOPP) registry is an international prospective study that -previously described the impact of diffuse-type tenosynovial giant cell tumour (D-TGCT) on patient-reported outcomes (PROs) from a baseline snapshot. This analysis describes the impact of D-TGCT at 2-year follow-up based on treatment strategies. MATERIAL AND METHODS: TOPP was conducted at 12 sites (EU: 10; US: 2). Captured PRO measurements assessed at baseline, 1-year, and 2-year follow-ups were Brief Pain Inventory (BPI), Pain Interference, BPI Pain Severity, Worst Pain, EQ-5D-5L, Worst Stiffness, and -Patient-Reported Outcomes Measurement Information System. Treatment interventions were no current/planned treatment (Off-Treatment) and systemic treatment/surgery (On-Treatment). RESULTS: A total of 176 patients (mean age: 43.5 years) were included in the full analysis set. For patients without active treatment strategy -(Off-Treatment) at baseline (n = 79), BPI Pain Interference (1.00 vs. 2.86) and BPI Pain Severity scores (1.50 vs. 3.00) were numerically favorable in patients remaining Off-Treatment compared with those who switched to an active treatment strategy at year 1. From 1-year to 2-year -follow-ups, patients who remained Off-Treatment had better BPI Pain Interference (0.57 vs. 2.57) and Worst Pain (2.0 vs. 4.5) scores compared with patients who switched to an alternative treatment strategy. In addition, EQ-5D VAS scores (80.0 vs. 65.0) were higher in patients who remained -Off-Treatment between 1-year and 2-year follow-ups compared with patients who changed treatment strategy. For patients receiving systemic treatment at baseline, numerically favorable scores were seen in patients remaining on systemic therapy at 1-year follow-up: BPI Pain Interference (2.79 vs. 5.93), BPI Pain Severity (3.63 vs. 6.38), Worst Pain (4.5 vs. 7.5), and Worst Stiffness (4.0 vs. 7.5). From 1-year to 2-year follow-up, EQ-5D VAS scores (77.5 vs. 65.0) were higher in patients who changed from systemic treatment to a different treatment strategy. CONCLUSION: These findings highlight the impact D-TGCT has on patient quality of life, and how treatment strategies may be influenced by these outcome measures. (ClinicalTrials.gov number: NCT02948088).

Effectiveness of arthroscopic excision based on the distribution of the tenosynovial giant cell tumor around knee joint.

BACKGROUND: The mainstay treatment for tenosynovial giant cell tumor (TGCT) is open excision. However, open excision is associated with the risk of stiffness, infection, neurovascular injury, and prolonged hospital stay and rehabilitation. The purpose of this study was to evaluate the efficacy of arthroscopic excision of tenosynovial giant cell tumor (TGCT) of the knee joint, including the diffuse type of TGCT. METHODS: Patients who underwent arthroscopic excision of TGCT between April 2014 and November 2020 were retrospectively analyzed. TGCT lesions were divided into 12 distributions (nine intra- and three extra-articular lesions). The distribution of TGCT lesions, portals used, degree of excision, recurrence, and magnetic resonance imaging (MRI) scans were evaluated. The prevalence of intra-articular lesions in diffuse TGCT was also analyzed to validate the existence of a connection between intra- and extra-articular lesions. RESULTS: Twenty-nine patients were included in the study. Fifteen patients (52%) had localized TGCT, and 14 patients (48%) had diffuse TGCT. The recurrence rates for localized, and diffuse TGCT were 0%, and 7%, respectively. Intra-articular posteromedial (i-PM), intra-articular posterolateral (i-PL), and extra-articular posterolateral (e-PL) lesions were found in all patients with diffuse TGCT. The prevalence rates of i-PM and i-PL lesions among e-PL lesions were both 100% (p = 0.026 and p < 0.001, respectively). Diffuse TGCT lesions were managed with posterolateral capsulotomy and viewed from the trans-septal portal. CONCLUSIONS: Arthroscopic excision of TGCT was effective in both localized and diffuse TGCT. However, diffuse TGCT was associated with posterior and extra-articular lesions. Therefore, technical modification such as posterior, trans-septal portal, and capsulotomy were required. STUDY DESIGN: Retrospective case series; level Ⅳ.

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.

Long-term Outcomes of Diffuse or Recurrent Tenosynovial Giant Cell Tumor Treated with Postoperative External Beam Radiation Therapy.

PURPOSE: Tenosynovial giant cell tumor (TGCT) is a rare proliferative disorder of synovial membrane that previously was known as pigmented villonodular synovitis. Primary treatment involves surgical resection; however, complete removal of all disease involvement is difficult to achieve. Radiation may be useful to reduce the risk of recurrence. We report and update our institutional experience treating diffuse and recurrent TGCT with postsurgical external beam radiation therapy. METHODS AND MATERIALS: We performed a retrospective chart review of 30 patients with TGCT from 2003 to 2019 treated with radiation therapy. Each patient was evaluated for demographics, radiation treatment parameters, surgical management, complications, and outcome. RESULTS: With mean follow-up of 82 months (range, 3-211), 24 patients (80%) who underwent surgery followed by radiation therapy did not experience any further relapse, and all 30 patients achieved local control (100%) with additional salvage therapy after radiation therapy. The most common site of disease was the knee (n = 22, 73%), followed by the ankle (n = 5, 16%) and the hand (n = 3, 10%). Seven patients (24%) presented at time of initial diagnosis and 23 (76%) presented with recurrent disease after surgical resection, with an average of 2.6 surgical procedures before radiation therapy. After resection, 18 of 30 patients (67%) demonstrated residual TGCT by imaging. The median radiation therapy dose delivered was 36 Gy (range, 34-36 Gy) in 1.8 to 2.5 Gy/fractions for 4 weeks. In the assessment of posttreatment joint function, 26 sites (86%) exhibited excellent or good function, 2 (7%) fair, and 2 poor (7%) as determined by our scoring system. There were no cases of radiation-associated malignancy. CONCLUSIONS: Among patients with diffuse or recurrent TGCT, postsurgical external beam radiation therapy provided excellent local control and good functional status, with minimal treatment-related complications. Postsurgical radiation therapy is a well-tolerated noninvasive treatment that should be considered after maximal cytoreductive resection to prevent disease progression and recurrence.

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.

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.

Tenosynovial giant cell tumours of the upper and lower cervical spine: two case reports.

INTRODUCTION: Tenosynovial giant cell tumours (TSGCTs) usually arise from the synovial membranes of tendon sheaths, bursa, and joints. They are rarely found in the spine. Lesions of the upper cervical spine (C1/2) are extremely rare, with only 13 previous cases reported in the literature. Of these, all previous anterior upper cervical cases (C1/2) have been deemed unresectable and have been managed with immunotherapy or radiological surveillance. CASE PRESENTATION: We report two cases of TSGCST in the cervical spine: one with a lesion at C1/2 and another at C6/7. DISCUSSION: The location of our C1/2 lesion was unique, allowing for a new endoscopic endonasal tissue biopsy method and a new transoral surgical approach for successful gross total resection. Our C6/7 lesion had a more typical location and was removed via a C6/7 laminectomy.