Molecular pathways involved in synovial cell inflammation and tumoral proliferation in diffuse pigmented villonodular synovitis

Outcomes of Surgical Treatment for Localized Tenosynovial Giant-Cell Tumor of the Foot and Ankle: A Case Series

Background

Giant cell tumor of the tendon sheath (GCTTS), also termed Tenosynovial giant cell tumor (TGCT), is a locally aggressive tumor which originates from tendon sheaths or bursas. Around 3-5% of these tumors arise from foot and ankle. Localized lesions in this area are often manifested as firm masses or nodules with slow but continuous progression through months and years. Pain associated with weight-bearing, as well as limitations in joint motions, may be reported, depending on tumor's location. Surgery is the treatment of choice for the definitive removal of GCTTSs with the aim to eradicate the neoplasm and restore the lower limb's functionality.

Methods

Thirteen cases suffering from GCTTS of the foot and ankle underwent surgical resection at our institution between 2017 and 2022. For each case we recorded pre-operative and post-operative symptoms, as well as their pre-operative and post-operative functional status according to both MSTS and AOFAS scores. Eventual complications and local recurrences were reported.

Results

Each patient experienced an at least mild pain before surgical treatment. The mean pre-operative MSTS and AOFAS scores were 22.8 and 70.7, respectively. The mean tumor size was 17.7 mm. Each patient received a resection with wide margins. Two cases (15.4%) had local recurrences. None had major complications at their latest follow-up. After the surgery, the mean post-operative MSTS and AOFAS scores increased to 28.3 and 92.2, respectively.

Conclusion

Resection with wide margins for foot and ankle GCTTS is effective in restoring the patients' lower limb functionality and is associated with reasonable local recurrence rates.

Surgical Techniques and Functional Reconstruction for Complex Tenosynovial Giant Cell Tumor of Temporal Bone and Middle Skull Base

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.

Increased expression of CSF1 in patients with eosinophilic asthma

BACKGROUND

The link between colony-stimulating factor 1 (CSF1) and asthma was reported recently. However, the role and mechanism of CSF1 in asthma remain poorly understood. In this study, we aimed to explore the expression and its potential mechanism of CSF1 in asthma.

METHODS

CSF1 expression in the airway samples from asthmatics and healthy controls were examined, then the correlations between CSF1 and eosinophilic indicators were analyzed. Subsequently, bronchial epithelial cells (BEAS-2B) with CSF1 overexpression and knockdown were constructed to investigate the potential molecular mechanism of CSF1. Finally, the effect of CSF1R inhibitor on STAT1 was investigated.

RESULTS

The expression of CSF1 was significantly increased in patients with asthma compared to healthy controls, especially in patients with severe and eosinophilic asthma. Upregulated CSF1 positively correlated with airway-increased eosinophil inflammation. In vitro, cytokines interleukin 13 (IL-13) and IL-33 can stimulate the upregulation of CSF1 expression. CSF1 overexpression enhanced p-CSF1R/CSF1R and p-STAT1/STAT1 expression, while knockdown CSF1 using anti-CSF1 siRNAs decreased p-CSF1R/CSF1R and p-STAT1/STAT1 expression. Furthermore, the inhibitor of CSF1R significantly decreased p-STAT1/STAT1 expression.

CONCLUSIONS

Sputum CSF1 may be involved in asthmatic airway eosinophil inflammation by interacting with CSF1R and further activating the STAT1 signaling. Interfering this potential pathway could serve as an anti-inflammatory therapy for asthma.

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.

The Clinical Effect of Topical Application of Tranexamic Acid in Arthroscopic Synovectomy of Pigmented Villonodular Synovitis of the Knee

This study investigated the clinical effect of topical application of tranexamic acid (TXA) in arthroscopic synovectomy of pigmented villonodular synovitis (PVNS) of the knee. Eighty patients who were diagnosed with unilateral knee PVNS underwent arthroscopic synovectomies from January 2017 to January 2021 and were retrospectively investigated in this study. Patients were divided into two groups: group A was the control group, whereas patients in group B received an intra-articular injection of 50 mL of TXA (1 g:100 mL) immediately after the synovectomies. The primary outcome measurement was the drainage volume of the affected knee in each postoperative stage, as well as the hematological parameters. Secondary outcomes included visual analog scale score, knee range of motion, and Lysholm score. Postoperative complications were also recorded. A lower volume of drainage was found in group B than in group A on postoperative day (POD) 1, on POD 2, and in total (POD 1, P=.000; POD 2, P=.000; total, P=.000). A lower visual analog scale pain score in group B was noticed on POD 1 (P=.000) and POD 2 (P=.005). Range of motion (P=.019) and Lysholm score (P=.001) were significantly superior in group B compared with group A on POD 14. Regarding complications, 3 patients in group A and 1 patient in group B developed deep venous thrombosis after surgery. Hematomas were found intra-articularly in 5 patients in group A during follow-up. Intraarticular topical application of TXA was effective in reducing postoperative bleeding and early postoperative pain for patients who underwent arthroscopic synovectomy of PVNS. [Orthopedics. 20XX;XX(X):xx-xx.].

Intra-labral pigmented villonodular synovitis: a rare case in two adult patients

This article discusses two rare cases of intra-labral pigmented villonodular synovitis (PVNS) of the hip. The hip joint represents the second most common location of pigmented villonodular synovitis, second to the knee [1]. The majority of hip PVNS cases either diffusely involve the synovium or are focal lesions within the joint. The lesions and synovium show foci of low signal intensity related to hemosiderin deposition, a finding that differentiates PVNS from other causes of synovial proliferation. Our case report presents two rare manifestations of PVNS lesions localized within the hip labrum. This presentation could easily be mistaken for a cyst by imaging modality. Despite the rarity of this condition, we highlight the importance of questioning the possibility of intra-labral PVNS, when patients have persistent hip pain not responding to therapy and atypical imaging findings. Highlighting this rare presentation is crucial for establishing the correct diagnosis, guiding treatment, and obtaining the best clinical outcome.

Tenosynovial giant cell tumors (TGCT): molecular biology, drug targets and non-surgical pharmacological approaches

INTRODUCTION

Tenosynovial giant cell tumor (TGCT) is a mono-articular, benign or locally aggressive and often debilitating neoplasm. Systemic therapies are becoming part of the multimodal armamentarium when surgery alone will not confer improvements. Since TGCT is characterized by colony-stimulating factor-1 (CSF1) rearrangements, the most studied molecular pathway is the CSF1 and CSF1 receptor (CSF1R) axis. Inhibiting CSF1-CSF1R interaction often yields considerable radiological and clinical responses; however, adverse events may cause treatment discontinuation because of an unfavorable risk-benefit ratio in benign disease. Only Pexidartinib is approved by the US FDA; however, the European Medicines Agency has not approved it due to uncertainties on the risk-benefit ratio. Thus, there is a need for safer and effective therapies.

AREAS COVERED

Light is shed on disease mechanisms and potential drug targets. The safety and efficacy of different systemic therapies are evaluated.

EXPERT OPINION

The CSF1-CSF1R axis is the principal drug target; however, the effect of CSF1R inhibition on angiogenesis and the role of macrophages, which are essential in the postoperative course, needs further elucidation. Systemic therapies have a promising role in treating mainly diffuse-type, TGCT patients who are not expected to clinically improve from surgery. Future drug development should focus on targeting neoplastic TGCT cells.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Gene Expression Profiles Analyzed Using Integrating RNA Sequencing, and Microarray Reveals Increased Inflammatory Response, Proliferation, and Osteoclastogenesis in Pigmented Villonodular Synovitis

Background

Pigmented villonodular synovitis (PVNS) is a rare condition that involves benign proliferation of the synovial tissue and is characterized by severe joint destruction and high recurrence even after surgical resection. However, poor understanding of the pathogenesis limits its effective therapy.

Method

In this study, gene expression profiles of six patients with PVNS, 11 patients with osteoarthritis (OA), nine patients with rheumatoid arthritis (RA) (E-MTAB-6141), and three healthy subjects (GSE143514) were analyzed using integrating RNA sequencing (RNA-seq) and microarray to investigate the PVNS transcriptome. Gene ontology, string, and cytoscape were used to determine the gene functional enrichment. Cell functional molecules were detected using flow cytometry or immunohistochemical test to identify the cell subset and function. CD14⁺ cells were isolated and induced to osteoclast to evaluate the monocyte/macrophage function.

Results

The most obvious local manifestations of PVNS were inflammation, including increased immune cells infiltration and cytokine secretion, and tumor phenotypes. High proportion of inflammatory cells, including T cells, natural killer (NK) cells, NKT cells, and B cells were recruited from the blood. Th17 and monocytes, especially classical monocytes but not nonclassical monocytes, increased in PVNS synovium. An obvious increase in osteoclastogenesis and macrophage activation was observed locally. Elevated expression of MMP9, SIGLEC 15, and RANK were observed in myeloid cell of PVNS than OA. When compared with RA, osteoclast differentiation and myeloid cell activation are PVNS-specific characters, whereas T cell activation is shared by PVNS and RA.

Conclusion

The transcriptional expression characteristics of PVNS showed increased immune response, cell migration, and osteoclastogenesis. Osteoclast differentiation is only observed in PVNS but not RA, whereas T-cell activation is common in inflammatory arthritis.

Tenosynovial giant cell tumor involving the cervical spine: A case report

BACKGROUND

Tenosynovial giant cell tumors (TGCTs) are a frequent benign proliferative disease originating from the synovial membrane. However, TGCTs rarely occur in the spine. The purpose of this paper is to report a case of TGCT occurring in the cervical spine. Although the disease is rare, it is essential to consider the possibility of TGCT in axial skeletal lesions. Awareness of spinal TGCTs is important because their characteristics are similar to common spinal tumor lesions.

CASE SUMMARY

A 49-year-old man with a 2-year history of neck pain and weakness in both lower extremities was referred to our ward. Imaging revealed a mass extending from the left epidural space to the C4-5 paravertebral muscles with uneven enhancement. The tumor originated in the synovium of the C4-5 lesser joint and eroded mainly the C4-5 vertebral arch and spine. Puncture biopsy was suggestive of a giant cell-rich lesion. The patient had pulmonary tuberculosis, and we first administered anti-tuberculosis treatment. After the preoperative requirements of the anti-tuberculosis treatment were met, we used a posterior cervical approach to completely remove the mass after fixation with eight pedicle screws. The mass was identified as a TGCT by postoperative immunohistochemical analysis. Recurrence was not detected after 1 year of follow-up.

CONCLUSION

Spinal TGCTs are often misdiagnosed. The radiological changes are not specific. The ideal treatment comprises complete excision with proper internal fixation, which can significantly reduce postoperative recurrence.

Patient-Derived Tumor Xenografts Plus Ex Vivo Models Enable Drug Validation for Tenosynovial Giant Cell Tumors

INTRODUCTION

Tenosynovial giant cell tumor (TGCT) is a locally aggressive tumor with colony-stimulating factor 1 receptor (CSF1R) signal expression. However, there is a lack of better in vivo and ex vivo models for TGCT. This study aims to establish a favorable preclinical translational platform, which would enable the validation of efficient and personalized therapeutic candidates for TGCT.

PATIENTS AND METHODS

Histological analyses were performed for the included patients. Fresh TGCT tumors were collected and sliced into 1.0-3.0 mm³ sections using a sterilized razor blade. The tumor grafts were surgically implanted into subrenal capsules of athymic mice to establish patient-derived tumor xenograft (PDTX) mouse models. Histological and response patterns to CSF1R inhibitors evaluations were analyzed. In addition, ex vivo cultures of patient-derived explants (PDEs) with endpoint analysis were used to validate TGCT graft response patterns to CSF1R inhibitors.

RESULTS

The TGCT tumor grafts that were implanted into athymic mice subrenal capsules maintained their original morphological and histological features. The "take" rate of this model was 95% (19/20). Administration of CSF1R inhibitors (PLX3397, and a novel candidate, WXFL11420306) to TGCT-PDTX mice was shown to reduce tumor size while inducing intratumoral apoptosis. In addition, the CSF1R inhibitors suppressed circulating nonspecific monocyte levels and CD163-positive cells within tumors. These response patterns of engrafts to PDTX were validated by ex vivo PDE cultures.

CONCLUSIONS

Subrenal capsule supports the growth of TGCT tumor grafts, maintaining their original morphology and histology. This TGCT-PDTX model plus ex vivo explant cultures is a potential preclinical translational platform for locally aggressive tumors, such as TGCT.

cIAP2 expression and clinical significance in pigmented villonodular synovitis

Pigmented villonodular synovitis (PVNS) is a rare hyperplasia disease of the synovium with a predilection for the knee in either a localized (LPVNS) or a diffuse form (DPVNS). But the exact cause is not clear. The aim of this study was to explore the relationship between the expression of cellular inhibitor of apoptosis 2 (cIAP2) and proliferation, apoptosis, invasive growth and postoperative recurrence in PVNS. Clinical significance of cIAP2 expression in synovium from 63 patients' knee joints with PVNS (40 DPVNS; 23 LPVNS) were investigated with 20 normal subjects acting as controls. The cIAP2 gene was screened by Human Cancer Pathway Finder PCR Array and real-time polymerase chain reaction (RT-PCR). We also used immunohistochemistry to detect cIAP2 and proliferating cell nuclear antigen (PCNA) protein expression and analyzed their relationship with PVNS type, invasive growth, and postoperative recurrence. The expression of cIAP2, PCNA, caspase-8, caspase-9 and caspase-3 protein was tested in Western blot. Screening results of Human Cancer Pathway Finder PCR array and RT-PCR showed significantly more cIAP2 mRNA in DPVNS synovium than in normal or LPVNS synovium (P < 0.05). Immunohistochemistry and western blot showed that the cIAP2 protein expression level in DPVNS was significantly higher than in LPVNS tissue (P < 0.01). As cIAP2 expression increased, the expression of PCNA increased (P < 0.05) and expression of cleaved caspase-3, -8, -9 decreased (P < 0.01). cIAP2 and PCNA overexpression were found to be related to ligament and bone erosion in PVNS and to disease recurrence (P < 0.05). This study suggested that cIAP2 overexpression plays an important role in the anti-apoptotic, proliferative and invasive growth of PVNS, which may account for the recurrence and poor prognosis of DPVNS.

Multiple systemic treatment options in a patient with malignant tenosynovial giant cell tumour

Tenosynovial giant cell tumour (TGCT) is a group of rare soft tissues neoplasia affecting synovial joints, bursae and tendon sheaths and is classified as localized type or diffuse type. The diffuse type (TGCT-D), also known as 'pigmented villonodular (teno)synovitis' is characterized by local aggressivity, with invasion and destruction of adjacent soft-tissue structures, and high local recurrence rate. Radical surgery remains the standard therapy while adjuvant radiotherapy may help to control local spread. Malignant TGCT is characterized by high rate of local recurrences and distant metastasis. Few cases of malignant TGCT and very few evidences on systemic therapies are described in the literature, so, to date, no systemic treatment is approved for this rare disease. We report the case of a malignant TGCT patient treated with many different systemic therapies, including chemotherapy and tyrosine-kinase inhibitors, and performed a review of the literature on the systemic treatment options of this rare tumour.

Giant cell tumor of tendon sheath in the wrist that damaged the extensor indicis proprius tendon: a case report and literature review

BACKGROUND

Giant cell tumor of the tendon sheath (GCTTS) is a benign soft tissue (synovial membrane) tumor that rarely involves the hands or wrists. And Tendon impairment caused by GCTTS is extremely rare.

CASE PRESENTATION

Here, we reported a case of a 60-year-old female with a 10-year history of gradually increasing mass in her left dorsal wrist. The EIP tendon was partially impaired by the mass.The patient was treated with surgical excision of the mass and reconstruction of the EIP tendon. The histopathological examination suggested the presence of GCTTS. After surgery, the patient had adequate functional recovery and no tumor recurrence after 2 years' follow-up.

CONCLUSION

GCTTS in hands and wrists rarely damages the tendon. Early diagnosis and proactive interventions may likely contribute to good prognostic outcomes.

Distinct extra-articular invasion patterns of diffuse pigmented villonodular synovitis/tenosynovial giant cell tumor in the knee joints

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.

Bone Remodeling and the Role of TRAF3 in Osteoclastic Bone Resorption

Skeletal health is maintained by bone remodeling, a process in which microscopic sites of effete or damaged bone are degraded on bone surfaces by osteoclasts and subsequently replaced by new bone, which is laid down by osteoblasts. This normal process can be disturbed in a variety of pathologic processes, including localized or generalized inflammation, metabolic and endocrine disorders, primary and metastatic cancers, and during aging as a result of low-grade chronic inflammation. Osteoclast formation and activity are promoted by factors, including cytokines, hormones, growth factors, and free radicals, and require expression of macrophage-colony stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL) by accessory cells in the bone marrow, including osteoblastic and immune cells. Expression of TNF receptor-associated factor 6 (TRAF6) is required in osteoclast precursors to mediate RANKL-induced activation of NF-κB, which is also necessary for osteoclast formation and activity. TRAF3, in contrast is not required for osteoclast formation, but it limits RANKL-induced osteoclast formation by promoting proteasomal degradation of NF-κB-inducing kinase in a complex with TRAF2 and cellular inhibitor of apoptosis proteins (cIAP). TRAF3 also limits osteoclast formation induced by TNF, which mediates inflammation and joint destruction in inflammatory diseases, including rheumatoid arthritis. Chloroquine and hydroxychloroquine, anti-inflammatory drugs used to treat rheumatoid arthritis, prevent TRAF3 degradation in osteoclast precursors and inhibit osteoclast formation in vitro. Chloroquine also inhibits bone destruction induced by ovariectomy and parathyroid hormone in mice in vivo. Mice genetically engineered to have TRAF3 deleted in osteoclast precursors and macrophages develop early onset osteoporosis, inflammation in multiple tissues, infections, and tumors, indicating that TRAF3 suppresses inflammation and tumors in myeloid cells. Mice with TRAF3 conditionally deleted in mesenchymal cells also develop early onset osteoporosis due to a combination of increased osteoclast formation and reduced osteoblast formation. TRAF3 protein levels decrease in bone and bone marrow during aging in mice and humans. Development of drugs to prevent TRAF3 degradation in immune and bone cells could be a novel therapeutic approach to prevent or reduce bone loss and the incidence of several common diseases associated with aging.

Long-term outcome of pigmented villonodular synovitis of the hip after joint preserving therapy

INTRODUCTION

Pigmented villonodular synovitis (PVNS) is a rare, destructive synovial disease that affects the hip joint the second most common after the knee. However, in contrast, joint preserving surgery in the hip joint is considered to be significantly more difficult or even impossible due to earlier occurrence of osteochondral dissemination and surgical difficulties. Today, earlier diagnosis due to the generous use of MRI and modern surgical strategies raise hope for improved outcomes.

METHODS

Since 2005, six patients with PVNS of the hip and a minimal follow-up of 2 years underwent joint preserving surgery in our institution (mean age 20.5 years, range 14-27). After PVNS was suspected in the MRI and confirmed by arthroscopic biopsy (four diffuse, two focal forms), synovectomy was carried out in 5 patients via surgical hip dislocation and in one focal case via arthroscopy. In diffuse forms, adjuvant radiosynoviorthesis (RSO) was conducted 6-8 week postoperatively. MRI and clinical examinations were performed during follow-up.

RESULTS

After a mean follow-up of 8 years (range 35-141 months), five of six patients did not show recurrence or secondary osteoarthritis. Clinical outcome evaluation resulted in a mean modified Harris Hip Score of 91 points (range 67-100 points). A 21-year-old patient with a diffuse form and advanced osteochondral involvement at the time of diagnosis was eventually treated by total hip arthroplasty.

CONCLUSION

In cases without osteochondral involvement, recurrence-free long-term results without progression of joint degeneration can be achieved by joint preserving therapy.

[The diffuse giant cell tumor of tendon sheath with chondroid metaplasia in right temporomandibular joint: a case report]

A case diagnosed as diffuse giant cell tumor of tendon sheath with chondroid metaplasia in right temporomandibular joint was reported. The clinicopathological features, diagnosis, and treatment were discussed with the literature review.

Pigmented villonodular synovitis of the hip

Pigmented villonodular synovitis (PVNS) is a rare disease that can affect any joint, bursa or tendon sheath.The hip is less frequently affected than the knee, and hence is less discussed in scientific journals.PVNS of the hip mainly occurs in young adults, requiring early diagnosis and adequate treatment to obtain good results.There is no consensus on the management of PVNS of the hip in current literature.We will discuss the options for surgical intervention in hip PVNS using a literature review of clinical, biological, etiological, histological and radiographic aspects of the disease. Cite this article: Steinmetz S, Rougemont A-L, Peter R. Pigmented villonodular synovitis of the hip. EFORT Open Rev 2016;1:260-266. DOI: 10.1302/2058-5241.1.000021.

Combined arthroscopic and open synovectomy for diffuse pigmented villonodular synovitis of the knee

PURPOSE

There are few reports detailing recurrence rates or functional outcomes after combined arthroscopic and open synovectomy to treat diffuse pigmented villonodular synovitis (DPVNS) of the knee.

METHODS

Patients with DPVNS of the knee treated with combined synovectomy, followed for a minimum of 12 months at a tertiary orthopaedic oncology centre, were identified. We extracted data pertaining to demographics, complications, clinical outcomes and recurrence. Functional status was evaluated prospectively using the Toronto Extremity Salvage Score (TESS) and the Musculoskeletal Tumor Society (MSTS) 1987 and 1993 surveys. Data were reported descriptively as mean (SD) unless otherwise specified.

RESULTS

Fifteen patients [80% female; mean age 38.9 (SD 14.2) years] representing 15 knees were treated with combined synovectomies and followed for 81 (SD 55) months. Posterior arthroscopy was utilized in 73% of patients. External beam radiation was utilized post-operatively in 73% of patients. Two patients (13%) experienced symptomatic disease recurrence. The mean post-operative knee range of motion was 1° (range 0-10°) to 115° (range 90-135°). TESS and MSTS 1987/1993 scores all suggested excellent patient function. Post-operative complications included one posterior wound dehiscence, one case of femoral condyle avascular necrosis and one patient with lymphedema.

CONCLUSIONS

Combined synovectomy resulted in a low rate of symptomatic disease recurrence and good to excellent functional outcomes for diffuse PVNS of the knee. A literature review identified this as largest case series focusing on combined synovectomies for DPVNS of the knee and the only one describing functional outcomes or the use of external beam radiotherapy.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Imatinib mesylate induces mitochondria-dependent apoptosis and inhibits invasion of human pigmented villonodular synovitis fibroblast-like synovial cells

Pigmented villonodular synovitis (PVNS) is a rare sarcoma-like disorder characterized by synovial lesions proliferation and invasion to articular cartilage for which no effective treatments are available. Imatinib mesylate (IM) is known to exert antitumor activity in some tumors, but its effects on PVNS fibroblast-like synoviocytes (PVNS-FLS) and the specific mechanism involved remain to be established. In the present study, the in vitro effects of IM on cell proliferation and survival rates were investigated in PVNS-FLS. Apoptosis induction was assessed via acridine orange/ethidium bromide (AO)/(EB) and Annexin V/PI staining as well as western blotting. The invasion ability of PVNS-FLS was evaluated by Transwell invasion chambers. IM significantly inhibited survival and invasion ability of PVNS-FLS in a dose- and time-dependent manner. The drug-treated cell groups exhibited markedly higher apoptosis, which was blocked upon pretreatment with the specific caspase-9 inhibitor Z-LEHD-FMK. Expression of cleaved caspase-9 was significantly increased and the Bcl-2 family and caspase-3 were activated following treatment with IM. Our results collectively demonstrated that IM has a strong antiproliferative effect on PVNS-FLS in vitro, attributable to induction of mitochondrial-dependent apoptosis in association with activation of caspase-9/-3 and the Bcl-2/Bax family, and exhibits significant inhibition on the invasion ability of PVNS-FLS, suggesting that IM may be useful as a novel treatment of this disease.

The effect of surgical synovectomy and radiotherapy on the rate of recurrence of pigmented villonodular synovitis of the knee

Pigmented villonodular synovitis (PVNS) is a rare proliferative process of the synovium which most commonly affects the knee and occurs in either a localised (LPVNS) or a diffuse form (DPVNS). The effect of different methods of surgical synovectomy and adjuvant radiotherapy on the rate of recurrence is unclear. We conducted a systematic review and identified 35 observational studies in English which reported the use of surgical synovectomy to treat PVNS of the knee.

A meta-analysis included 630 patients, 137 (21.8%) of whom had a recurrence after synovectomy. For patients with DPVNS, low-quality evidence found that the rate of recurrence was reduced by both open synovectomy (odds ration (OR) = 0.47; 95% CI 0.25 to 0.90; p = 0.024) and combined open and arthroscopic synovectomy (OR = 0.19, 95% CI = 0.06 to 0.58; p = 0.003) compared with arthroscopic surgery. Very low-quality evidence found that the rate of recurrence of DPVNS was reduced by peri-operative radiotherapy (OR = 0.31, 95% CI 0.14 to 0.70; p = 0.01). Very low-quality evidence suggested that the rate of recurrence of LPVNS was not related to the surgical approach.

This meta-analysis suggests that open synovectomy or synovectomy combined with peri-operative radiotherapy for DPVNS is associated with a reduced rate of recurrence. Large long-term prospective multicentre observational studies, with a focus on both rate of recurrence and function, are required to confirm these findings.

Cite this article: Bone Joint J 2015;97-B:550–7.

A comparison of open and arthroscopic surgery for treatment of diffuse pigmented villonodular synovitis of the knee

PURPOSE

To compare the outcomes of diffuse pigmented villonodular synovitis (PVNS) of the knee treated with routine anteroposterior open surgery or modified multi-directional arthroscopy.

METHODS

Medical records of patients with diffuse PVNS who underwent surgery between 2002 and 2010 were reviewed. Patients were followed up at 3, 6, 12, 24, and 36 months. Operative time, blood loss, length of hospital stay, recurrence rate, and International Knee Documentation Committee (IKDC) scores and Lysholm knee scores at 1- and 3-year postoperatively were compared between the open surgery and arthroscopy groups.

RESULTS

A total of 41 patients with diffuse PVNS were included (20 in open surgery group and 21 in multi-directional arthroscopy group). There was no significant difference in the baseline characteristics between the two groups. Operation time, postoperative bleeding, and length of hospital stay were all significantly lower in the arthroscopy group than in the open surgery group (all, P < 0.05). There were four recurrences in the open surgery group and one in arthroscopy group. All five recurrences received a second surgery without any subsequent recurrences. At both 1- and 3-year postoperatively, IKDC and Lysholm scores were significantly greater in the arthroscopy group than the open surgery group (all P < 0.001).

CONCLUSIONS

The multi-directional arthroscopic technique was associated with significantly shorter operation time and hospital stay, less blood loss, and better postoperative IKDC and Lysholm scores than open surgery.

LEVEL OF EVIDENCE

Retrospective study with controls, Level III.

Hepatoid tenosynovial giant cell tumor - a rare morphologic variant case report

We report a morphologically rare type of tenosynovial giant cell tumor (TSGCT), localized type, occurring in a 49-year-old man. Imaging examination revealed multiple nodular lesions around the right knee joint. The largest one extended to both intra- and extra-osseous region of the right distal femur. Histologically, the tumor consisted of epithelioid mononuclear cells and they looked like to have abundant eosinophilic cytoplasm reminiscent of hepatic tissues. In some areas, however, typical histologic features of TSGCT were observed. Electron microscopy revealed that the eosinophilic cytoplasm-like substance was intercellular fibrinous material surrounding the mononuclear tumor cells. Immunohistochemically, mononuclear tumor cells and multinucleate giant cells were positive for CD68 (Kp1) and some of the mononuclear tumor cells were also positive for desmin. Finally, we made the diagnosis of hepatoid TSGCT.

Pigmented villonodular synovitis: current concepts about diagnosis and management

At present, the treatment strategies in patients with localized and diffuse forms of pigmented villonodular synovitis have more or less been standardized. However, these strategies are not optimal because high recurrence rates persist and studies with a sufficient level of evidence are lacking. This systematic review article describes all known treatment options for intra-articular pigmented villonodular synovitis and their clinical results. Based on this research, we provide guidelines to support physicians in making the optimal treatment decisions. Given the rarity of the disease, randomized studies are not to be expected, but an international registry through existing networks would offer the benefit of getting a better insight into the outcome of this disease. Therefore, we propose a basic set of data to be investigated and ideally to be reported on in such a registry.

The class III histone deacetylase sirtuin 1 in immune suppression and its therapeutic potential in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic debilitating disease of the joints. Both the innate and adaptive immune responses participate in the development and progression of RA. While several therapeutic reagents, such as TNF-α agonists, have been successfully developed for the clinical use in the treatment of RA, more than half of the patients do not respond to anti-TNF therapy. Therefore, new therapeutic reagents are needed. Recent studies have shown that sirtuin 1 (Sirt1), a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase, is a critical negative regulator of both the innate and adaptive immune response in mice, and its altered functions are likely to be involved in autoimmune diseases. Small molecules that modulate Sirt1 functions are potential therapeutic reagents for autoimmune inflammatory diseases. This review highlights the role of Sirt1 in immune regulation and RA.

Frequent upregulation of cyclin D1 and p16 expression with low Ki-67 scores in multinucleated giant cells

BACKGROUND/AIMS

Multinucleated giant cells are formed from the fusion of macrophages and are classified into foreign body-type giant cells (FBGCs), osteoclast-type giant cells (OCGCs) and Langhans-type giant cells (LHGCs). OCGCs display upregulated cyclin D1 expression with low Ki-67 activity. However, little is known about the expression of cell cycle regulators in the other types of multinucleated giant cells. We aimed to investigate the cell cycle status of multinucleated giant cells.

METHODS

The immunohistochemical expressions of cyclin D1, p16(INK4a) and Ki-67 were analyzed in a total of 127 cases showing multinucleated giant cells.

RESULTS

Cyclin D1 was overexpressed in 45 (88%) of 51 FBGC cases, 25 (86%) of 29 OCGC cases and 22 (47%) of 47 LHGC cases. p16(INK4a) showed diffuse nuclear and/or cytoplasmic overexpression in 45 (88%) of 51 FBGC cases, 27 (93%) of 29 OCGC cases and 24 (51%) of 47 LHGC cases. Ki-67 immunostaining was negative in almost all FBGC, OCGC and LHGC cases.

CONCLUSION

This study demonstrates that FBGCs and OCGCs frequently show upregulation of cyclin D1 and p16(INK4a) expression with low Ki-67 scores. This suggests that multinucleated giant cells are arrested in the G1/S cell cycle transition.