Synovial chondrosarcoma

Soft Tissue Sarcomas Mimicking Benign Inflammatory Processes: A Diagnostic Dilemma

Background

Soft tissue sarcomas are rare and often go undetected until a later stage, particularly when they present as intra-articular or tenosynovial lesions mimicking benign synovial pathologies. The failure to distinguish between malignant and benign synovial disease can have a significant impact on patient outcomes and limit alternatives for local control surgery and limb salvage.

Case Description

In this case series, we present two cases of soft tissue sarcomas, one being an intraarticular synovial chondrosarcoma, and the other a pleomorphic spindle cell sarcoma centred along tendon sheaths. Radiologically, the initial clinical presentation of these cases resembled benign synovial pathologies, leading to a delay in diagnosis and treatment.

Conclusion

Our study underscores the importance of maintaining a low threshold of suspicion for surveillance, a multidisciplinary approach, and early histological diagnosis to ensure appropriate timely treatment and a favourable prognosis for patients with soft tissue sarcomas.

A Sarcoma Masquerading as a Pseudotumor After Total Hip Arthroplasty: A Case Report

CASE

There is an increasing emphasis on adverse reactions to metal debris around prosthetic hip implants. We present a case report of a patient with increasing pain around a previous total hip arthroplasty and magnetic resonance imaging findings consistent with a pseudotumor. Serum metal ion levels were not elevated and initial biopsy findings inconclusive. The patient was diagnosed with an extraskeletal chondrosarcoma after revision total hip arthroplasty and subsequently underwent external hemipelvectomy with negative margins.

CONCLUSION

This report highlights the importance of remaining vigilant for malignant sarcomas presenting as pseudotumors around hip replacements, particularly in the absence of abnormal metal ion levels or definitive biopsy results.

Secondary Chondrosarcoma Arising in Synovial Chondromatosis of Wrist Joint

Introduction

Chondrosarcoma of the synovium is a rare and malignant form of cartilaginous tumor that originates in synovial tissue. There have only been a limited number of reported cases of malignant transformation of synovial chondromatosis (SC) into secondary chondrosarcoma (SCH), primarily in the hip and knee, in patients with resistant illness. The occurrence of chondrosarcoma in SC of the wrist is highly uncommon, as evidenced by only a single previous case study that has been documented in the literature.

Case Report

This study presents a case series of two patients with primary SC who developed SCH at the wrist joint.

Conclusion

Clinicians treating localized swellings of the hand and wrist should be alert to the likelihood of a sarcoma diagnosis to minimize delays to definitive therapy.

Temporomandibular joint synovial chondromatosis: An analysis of 7 cases and literature review

OBJECTIVE

To investigate the diagnosis and treatment procedure of synovial chondromatosis (SC) of the temporomandibular joint (TMJ).

METHODS

Clinical features, imaging features, surgical methods, and prognosis of 7 patients with SC of the TMJ were analyzed. We also reviewed and analyzed surgery-relevant literature included in the Pubmed database in the past decade using the search terms "synovial chondromatosis" and "temporomandibular joint", and found 181 cases.

RESULTS

There was no specific difference in the symptoms of SC in the TMJ in different Milgram's stages in our cases and the cases mentioned in the literature. The main symptoms of SC in the TMJ were pain (100%, 7/7; 64.64%, 117/181), limited mouth opening (57.14%, 4/7; 53.59%, 97/181), swelling (14.29%, 1/7; 28.18%, 51/181), crepitus (28.57%, 2/7; 19.34%, 35/181), and clicking (14.29%, 1/7; 9.94%, 18/181) in our cases and cases from literature separately. The imaging features of SC were occupying lesions (including loose bodies or masses) (71.42%, 5/7; 37.57%, 68/181), bone change in condyle or glenoid fossa (1/7, 14.29%; 34.81%, 63/181), effusion (42.86%, 3/7; 20.99%, 38/181), joint space changes (42.86%, 3/7; 11.05%, 20/181) in our cases and cases from literature separately. The surgical procedures seem to depend mainly on the involved structures and the extension of the lesion rather than the Milgram's stage.

CONCLUSIONS

The clinical features of SC in the TMJ are nonspecific and easy to be misdiagnosed. MRI is helpful in the diagnosis of SC in the TMJ. The surgical procedures mainly depend on the involved structures and the extension of the lesion.

Primäre synoviale Chondromatose

Hintergrund

Die primäre synoviale Chondromatose (SC) ist eine seltene Erkrankung der Synovialmembran unklarer Ätiologie. Der aktuelle Wissensstand zu dieser Erkrankung soll in einer kurzen Übersicht dargestellt werden.

Methoden

Übersichtsarbeiten und rezente Fallberichte zur SC wurden systematisch ausgewertet und mit Daten eigener Fälle in Kontext gesetzt.

Ergebnisse

Auf Grund neuer genomischer Daten wird die SC als benigne Neoplasie eingestuft. In 60 % der Fälle liegen Mutationen im Fibronektin-1-Gen (FN1) und/oder im Gen für den Activin-A-Typ-II-Rezeptor (ACVR2A) vor. Diagnoseweisend ist die Magnetresonanztomographie (MRT) und die meist arthroskopische Biopsie der Synovia. An einem Fallbeispiel soll gezeigt werden, dass die Knorpelaggregate der SC radiologisch nicht immer schattengebend sein müssen. Differenzialdiagnostisch kommen Monarthritiden anderer Ursachen, andere Gelenk- und Muskelerkrankungen mit Mineralisierung sowie weitere von der Synovialmembran ausgehende Erkrankungen in Betracht. Die Entartungsrate liegt bei 2–4 %. Therapeutisch hat sich in den letzten Jahren das arthroskopische Vorgehen durchgesetzt, das an die Ausdehnung der Erkrankung adaptiert wird.

Schlussfolgerung

Genomische Untersuchungen sowie Fallserien und Fallberichte aus jüngerer Zeit werfen ein neues Licht auf die SC. Therapeutisch wird in jüngeren Arbeiten überwiegend arthroskopisch vorgegangen.

Clinical comparison of tenosynovial giant cell tumors, synovial chondromatosis, and synovial sarcoma: analysis and report of 53 cases

Background

Tenosynovial giant cell tumors (TGCTs), synovial chondromatosis (SC), and synovial sarcoma (SS) exhibit similarities in clinical features and histochemical characteristics, and differential diagnosis remains challenging in clinical practice.

Methods

Data were collected from the pathology database of Shanghai Ninth People's Hospital regarding patients who underwent surgery from 2010 to 2019 with histologically confirmed TGCTs, SC, and SS. Demographic and clinicopathological data of these patients were reviewed. Immunohistochemistry staining of 14 different markers was performed. Correlation analyses of the prognoses were evaluated.

Results

A total of 26 patients with TGCTs (8 diffuse TGCTs and 18 localized TGCTs), 16 with SC, and 11 with SS were identified. Pain was the main symptom of patients with both TGCTs and SC, while a palpable mass was the most common symptom for patients with SS. In addition to clinical features, we identified vital risk factors for disease recurrence. The mean follow-up periods were 51, 39, and 14 months for TGCTs, SC, and SS, respectively. Younger patients with diffuse TGCTs or patients with a higher neutrophil/lymphocyte ratio (NLR) displayed a significantly higher frequency of recurrence. We also plotted receiver operating characteristic (ROC) curve analysis for age and NLR. The area under the ROC curve (AUC) was calculated and demonstrated the ability to distinguish recurrent from nonrecurrent cases. In addition, higher CD163 expression was linked to recurrent diffuse TGCT cases.

Conclusions

These data indicated possible characteristics of different aspects of TGCTs, SC, and SS. Further clarification and understanding of these factors will help with differential clinical diagnosis and recurrent risk assessment.

Anterior and Posterior Arthroscopic Treatment of Primary Synovial Chondromatosis of the Ankle

BACKGROUND

Primary synovial chondromatosis (PSC) is a progressive disorder of unknown etiology resulting in formation of multiple loose bodies. If left untreated, it may lead to degenerative changes or malignant transformation to chondrosarcoma.

METHODS

Seventeen patients who underwent combined posterior and anterior ankle arthroscopy within the same operative session and had histologically confirmed PSC were included in this retrospective study. American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot score was used to evaluate ankle function preoperatively and at a final follow-up. A 3-question survey was used to evaluate patient's satisfaction at the final follow-up.

RESULTS

In 14 patients, loose bodies were found in both compartments of the ankle, in 2 only in the anterior compartment, and in 1 only in the posterior compartment. All patients had evident signs of synovial inflammation in both compartments. The AOFAS Ankle-Hindfoot score increased from the preoperative median score of 65 (range, 29-90) to 95 (range, 65-100) at the final follow-up. Fourteen patients reported they were extremely satisfied with the outcome, 1 was moderately satisfied, and 2 were dissatisfied. No cases of recurrence of synovitis or loose body formation were noted, nor any signs of malignant transformation during the follow-up period.

CONCLUSION

We believe the risk of recurrence of PSC, which is in close relation to malignant transformation, can be minimized by performing a complete synovectomy of the ankle. Our experience and review of literature makes us believe that ankle PSC should be regarded as a whole joint disorder. Performing a combined posterior and anterior arthroscopic procedure within the same operative session should always be considered in patients with ankle PSC.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Synovial chondrosarcoma: a single-institution experience with molecular investigations and review of the literature

AIMS

To evaluate the available diagnostic histological criteria for synovial chondrosarcoma and to screen for the presence of IDH1/IDH2 mutations in a series of cases of this malignant cartilaginous neoplasm.

METHODS AND RESULTS

Ten cases of synovial chondrosarcoma diagnosed at our institute were reviewed. At presentation, all tumours occurred in adults (median age, 62 years). The most common location was the knee joint (five cases), and the size at diagnosis ranged from 30 mm to 170 mm. Eight patients had secondary synovial chondrosarcomas associated with pre-existing/recurrent or concomitant synovial chondromatosis. Five patients had local recurrences and three had lung metastases. All patients with intralesional excisions developed local recurrences, whereas those who underwent wide resections did not. At last follow-up (mean, 91 months), available for nine patients, seven patients were alive and disease-free, one patient had died of disease, and one was alive with paravertebral metastases. Frequent histological features observed included loss of clustering of chondrocytes (nine cases), the presence of variable amounts of myxoid matrix (eight cases), peripheral hypercellularity (eight cases), tumour necrosis (six cases), and spindling of chondrocytes (four cases). Of the seven cases for which it was possible to evaluate bone permeation, six showed infiltration of bone marrow. All seven cases screened for mutations of exon 4 of IDH1 and IDH2 were found to be wild-type.

CONCLUSIONS

Histological criteria in correlation with clinical and radiological features allow the recognition of synovial chondrosarcoma. IDH1/IDH2 mutations were not present in synovial chondrosarcoma. Adequate surgical margins are important for disease control.

Synovial chondromatosis and soft tissue chondroma: extraosseous cartilaginous tumor defined by FN1 gene rearrangement

A fusion between fibronectin 1 (FN1) and activin receptor 2A (ACVR2A) has been reported previously in isolated cases of the synovial chondromatosis. To analyze further and validate the findings, we performed FISH and demonstrated recurrent FN1-ACVR2A rearrangements in synovial chondromatosis (57%), and chondrosarcoma secondary to synovial chondromatosis (75%), showing that FN1 and/or AVCR2A gene rearrangements do not distinguish between benign and malignant synovial chondromatosis. RNA sequencing revealed the presence of the FN1-ACVR2A fusion in several cases that were negative by FISH suggesting that the true prevalence of this fusion is potentially higher than 57%. In soft tissue chondromas, FN1 alterations were detected by FISH in 50% of cases but no ACVR2A alterations were identified. RNA sequencing identified a fusion involving FN1 and fibroblast growth factor receptor 2 (FGFR2) in the case of soft tissue chondroma and FISH confirmed recurrent involvement of both FGFR1 and FGFR2. These fusions were present in a subset of soft tissue chondromas characterized by grungy calcification, a feature reminiscent of phosphaturic mesenchymal tumor. However, unlike the latter, fibroblast growth factor 23 (FGF23) mRNA expression was not elevated in soft tissue chondromas harboring the FN1-FGFR1 fusion. The mutual exclusivity of ACVR2A rearrangements observed in synovial chondromatosis and FGFR1/2 in soft tissue chondromas suggests these represent separate entities. There have been no reports of malignant soft tissue chondromas, therefore differentiating these lesions will potentially alter clinical management by allowing soft tissue chondromas to be managed more conservatively.

Malignant Transformation of Recurrent Synovial Chondromatosis: A Case Report and Review

Chondrosarcoma is the second most common primary malignant bone tumor. While the majority arrive de novo, a minority arise from malignant transformation of benign neoplasms, such as osteochondromas. Rarely, chondrosarcomas have been found to originate from other preexisting lesions, such as synovial chondromatosis. A 44-year-old male with a history of a spinal osteochondroma presented with one year of left hip pain and decreased range of motion. On examination, he had a palpable, irregular fullness in the left groin that was minimally tender to palpation. Radiographs and CT of the hip showed extensive soft tissue calcifications and erosion of the femoral neck. The lesion was debulked surgically and histologically diagnosed as synovial osteochondromatosis with no evidence of atypia or cellularity. One year later, his residual disease progressed and resulted in increasingly limited range of motion. He underwent left total hip arthroplasty with simultaneous debulking and the lesion was once again diagnosed as synovial osteochondromatosis. Two months postoperatively, the patient developed a new focus of calcification around the hip joint that was thought to be recurrent disease. Six months later, due to worsening symptoms, he underwent a repeat CT scan. This scan demonstrated extensive intra-articular disease extending into the iliopsoas bursa and around total hip arthroplasty, as well as a new soft tissue nodule with foci of calcification in the left gluteus maximus. The new lesion was debulked surgically and diagnosed as a grade 1 chondrosarcoma. Chondrosarcoma arising from synovial chondromatosis is a rare presentation of the second most common primary malignant bone tumor. It typically presents as an indolent, slowly growing painful mass of large joints in middle aged men. Conventional radiography shows punctate opacities, while MRI and CT reveal diffuse soft tissue calcification and cortical erosion. Low-grade chondrosarcomas are treated with intralesional curettage and adjuvant therapy, while higher grade chondrosarcomas are treated with wide, en bloc excision. Malignant transformation should be considered in any patient presenting with worsening symptoms and a history of a benign bony lesion.

Chondrosarcoma arising within synovial chondromatosis of the lumbar spine

Synovial chondromatosis is an uncommon benign neoplasm that usually affects large appendicular joints and only rarely the spine. There are only a few small series and case reports documenting malignant transformation of synovial chondromatosis into secondary chondrosarcoma, typically within the hip in the setting of recalcitrant disease and multiple recurrences. Chondrosarcoma arising in synovial chondromatosis of the spine is exceedingly rare, with only one previously published case report involving the craniocervical junction. We present a case of chondrosarcoma arising within synovial chondromatosis of the lumbosacral spine, with the diagnosis made at the time of initial presentation. We describe the clinical, imaging, and histopathological findings and review diagnostic criteria for this difficult diagnosis.

[Synovial fluid cytodiagnosis]

Synovial fluid samples represent only a very small percentage of routine work in a cytology laboratory. However, its microscopic examination allows us to observe different types of cells, particles and structures that, due to their morphological characteristics, may provide relevant data for cytodiagnosis. We present certain aspects related to arthrocentesis, the relationship between the gross appearance of synovial fluid and certain pathological processes, as well as the different techniques for processing and staining the smears. Furthermore, we describe the main cytological findings in various pathological conditions of the synovial joints, such as infections (bacterial and fungal), non-infectious inflammatory type (osteoarthrosis, rheumatoid arthritis, connective tissue diseases) and tumoral, distinguishing between primary and metastatic, both solid and haematological neoplasms.

Intra-articular synovial sarcoma in the ankle joint: A case report

Intra-articular primary soft tissue sarcomas are extremely rare. The present case report describes a case of intra-articular synovial sarcoma of the ankle joint. A 51-year-old man presented with complaints of swelling and progressive pain in the right ankle. Lateral radiographs of the ankle revealed lytic invasion of the anterior and posterior parts of the talus. Computed tomography imaging revealed a low-density lesion with calcifications around the ankle joint. Magnetic resonance imaging revealed that the diffuse lesion was isointense on T1-weighted images and hypointense to hyperintense on T2-weighted images. The final diagnosis was synovial sarcoma. The foot could not be salvaged as the sarcoma was diffusely spread throughout the ankle joint; thus, the patient underwent below-the-knee amputation with neoadjuvant and adjuvant chemotherapy. He succumbed from fatal arrhythmia 2 years following the initial diagnosis. Although intra-articular primary soft tissue sarcomas are extremely rare, the possibility of malignancy should be considered.

Arthroscopic Treatment of Synovial Chondromatosis in the Ankle Joint

Synovial chondromatosis of the ankle is rare and sparsely documented. Traditional surgical intervention is open loose body excision and synovectomy. Upon literature review, only two other cases were found to be managed arthroscopically. We report a case of synovial chondromatosis in a 54-year-old man leading to pain and limited range of motion of his ankle. This unique case of extensive nodule formation was treated via a three-port arthroscopic approach. Removal of loose bodies and synovectomy were successfully performed arthroscopically. A total of 76 loose bodies were removed and synovectomy performed using a 3.5 mm diameter full radius shaver. This case demonstrates that a three-port arthroscopic approach can provide adequate treatment while maintaining the superior risk profile inherent to arthroscopic intervention.