A molecular study of synovial chondromatosis.

Synovial chondromatosis (SC) is a rare benign cartilaginous neoplasm in which recurrent fibronectin 1 (FN1) and activin receptor 2A (ACVR2A) gene rearrangements have been recently reported. Triggered by a case of malignant transformation in SC (synovial chondrosarcoma) showing a novel KMT2A-BCOR gene fusion by targeted RNA sequencing, we sought to evaluate the molecular abnormalities in a cohort of 27 SC cases using a combined methodology of fluorescence in situ hybridization (FISH) and/or targeted RNA sequencing. Results showed that FN1 and /or ACVR2A gene rearrangements were noted in 18 cases (67%), with an FN1-ACVR2A fusion being confirmed in 15 (56%) cases. Two cases showed only FN1 gene rearrangement, without other abnormalities. A novel FN1-NFATc2 gene fusion was noted in one case by RNA sequencing. The remaining nine cases showed no abnormalities in FN1 and ACVR2A genes. No additional cases showed BCOR gene alterations. In conclusion, this study confirms that FN1-ACVR2A fusion is the leading pathogenetic event in SC, at even higher frequency than previously reported. FISH methodology emerges as an appropriate tool in the identification of FN1 and ACVR2A gene abnormalities, which can be used in challenging cases. Further studies are needed to determine the recurrent potential of BCOR abnormalities in this disease.

Synovial Chondromatosis and Calcium Pyrophosphate Deposition of the Temporomandibular Joint: Challenging Diagnosis.

BACKGROUND: The association between the synovial chondromatosis (SC) and the calcium pyrophosphate deposition (pseudogotta) in temporomandibular joint (TMJ) is very rare and has been described just 1 patient in the literature. CLINICAL PRESENTATION: A 64-year-old woman was referred to Dipartimento di Scienze Odontostomatologiche e Maxillo-Facciali, Sapienza Università di Roma after complaining about right temporomandibular pain, limitation in mandibular movements, and tumefaction in the right preauricular region. The patient was hospitalized for the surgery. The microscopic examination of the excised material revealed calcium pyrophosphate dihydrate (CPPD) deposits crystals associated with cartilaginous proliferation. CONCLUSION: The association between the SC and the calcium pyrophosphate deposition (pseudogotta) is a challenging diagnosis among TMJ neoplasms.

[Diagnosis and therapy of benign intraarticular tumors]. / Diagnostik und Therapie benigner intraartikulärer Tumoren.

Intraarticular benign tumors are rare lesions in many cases seen as incidental findings. One of the typical lesions is the diffuse or nodular form of pigmented villonodular synovitis, which needs a complete surgical removal. Magnetic Resonance Imaging (MRI) is diagnostic in most of the cases because of the intracellular iron content which shows an at least in some parts dark T2-sequence. Adjuvant therapies as radiosynoviorthesis should be considered in diffuse or recurrent lesions. Synovial Chondromatosis represents a metaplastic disorder of the synovial membrane resulting in the production of loose cartilage bodies. Also in this dissease synovectomy or, in late cases, removal of the loose bodies only, is recommended. Synovial hemangiomas are hamartomas which may lead to pain or restriction of movement. In these cases total or partial resection is justified. Alternative treatment options such as laserablation may be possible. Lipoma arborescens represents a proliferative lipoid lesion of the subsynovial region leading to villonodular synovial proliferation. If clinically symptomatic, resection by arthroscopic or open synovectomy is recommented.

Relapsing Polychondritis Concomitant With Synovial Chondromatosis of the Temporomandibular Joint.

Relapsing polychondritis (RP) is a rare, multisystem autoimmune disease characterized by inflammation, structural damage, and impaired function of cartilaginous tissues throughout the body. In the craniofacial region, this rare disease has been reported to affect structures of the ear and nose; however, reports of temporomandibular joint (TMJ) involvement are scarce. A second uncommon disorder of cartilage is synovial chondromatosis (SC), a progressive and proliferative disorder of the synovial membrane associated with the formation of variably sized cartilaginous and calcified loose bodies, often causing dysfunction of the joints and enlargement of the joint capsule. It commonly affects the larger joints; TMJ involvement is uncommon. We present the case of a 45-year-old woman with previously diagnosed RP in whom right TMJ pathology subsequently developed, undergoing arthroscopy and biopsy followed by arthroplasty, which was proved to be SC, likely due to her autoimmune disease. To our knowledge, this is the first case describing concomitant SC of the TMJ presumably from pre-existing RP.

Innovative Surgical Management of the Synovial Chondromatosis of Temporo-Mandibular Joints: Highly Conservative Surgical Technique.

Synovial chondromatosis (SC) is an uncommon disease characterized by a benign nodular cartilaginous proliferation arising from the joint synovium, bursae, or tendon sheaths. Although the temporomandibular joint is rarely affected by neoplastic lesions, SC is the most common neoplastic lesion of this joint. The treatment of this disease consists in the extraoral surgery with a wide removal of the lesion; in this study, the authors described a more conservative intraoral surgical approach. Patient with SC of temporomandibular joint typically refer a limitation in the mouth opening, together with a persistent not physiological mandibular protrusion and an appearance of a neoformation located at the right preauricular region: the authors reported 1 scholar patient. After biopsy of the neoformation, confirming the synovial chondromatosis, the patient underwent thus to the surgical excision of the tumor, via authors' conservative transoral approach, to facilitate the enucleation of the neoformation. The mass fully involved the pterygo-maxillary fossa with involvement of the parotid lodge and of the right TMJ: this multifocal extension suggested for a trans-oral surgical procedure, in the light of the suspicion of a possible malignant nature of the neoplasm. Our intraoral conservative approach to surgery is aimed to reduce the presence of unaesthetic scars in preauricular and facial regions, with surgical results undoubtedly comparable to the traditional surgical techniques much more aggressive. Our technique could be a valid, alternative, and safe approach to treat this rare and complex kind of oncological disease.

Tenosynovial Osteochondromatosis of the Flexor Hallucis Longus in a Division I Tennis Player.

Tenosynovial (extra-articular) chondromatosis (TC) is a condition characterized by the cartilaginous proliferation of synovial cells derived from the synovial lining of bursa and tendon sheaths. These lesions are often multinodular and most commonly present with complaints of swelling or pain. Treatment of TC primarily entails surgical excision. There are no known reports of TC in collegiate athletes. We present a case of TC in a Division I tennis player.

Secondary synovial chondromatosis of the shoulder.

Synovial chondromatosis is classified as either primary or secondary. Primary synovial chondromatosis results from a proliferation of chondrocytes in the synovial membrane leading to the formation of cartilaginous loose bodies. Secondary synovial chondromatosis is a rare condition characterized by the growth of separated particles from the articular cartilage or osteophytes in joint diseases. The present article aims to report the secondary chondromatosis of the shoulder and to discuss the clinical manifestations, pathogenesis, diagnosis, histological findings and management of this condition.

Chondroblastoma of the temporomandibular joint lateral capsule: a case report.

AIM: Chondroblastoma is a rare, benign bone tumor that accounts for approximately 1% of all primary bone tumors. Chondroblastoma that occurs at the temporomandibular joint can exhibit symptoms similar to those associated with other temporomandibular disorders. This case study aims to present an eight-year followup of chondroblastoma occurring at the temporomandibular joint. METHODOLOGY: The patient presented swelling in the left temporomandibular joint and trismus. Based oncomputed tomography and magnetic resonance imaging findings, a provisional diagnosis of synovial chondromatosis was made. Complete excision of the lesion was performed under general anesthesia. RESULTS: After histopathological examination, the lesion was finally diagnosed as chondroblastoma. Currently, 8 years after the operation, the patient has not experienced any symptoms or any notable complications. CONCLUSIONS: Although chondroblastoma is a benign tumor, it shows aggressive characteristics with bone invasion. Therefore, precise diagnosis and proper treatment planning is crucial for successful treatment of chondroblastoma.

Oncologic conditions that simulate common sports injuries.

Primary bone and soft-tissue tumors that mimic common sports injuries are relatively rare and are not often encountered by most orthopaedists. Prompt and accurate diagnosis of these tumors is crucial to maximize the clinical outcome. Many bone and soft-tissue tumors present disproportionately in young and active patients who are often involved in athletic activities. Thus, the clinician may misdiagnose these rare tumors as more common sports injuries. Symptoms that should raise suspicion for a neoplastic process include pain unrelated to activity and a clinical course that does not follow the typically expected recovery for a common sports injury. An awareness of the salient features of several bone and soft-tissue tumors as well as nononcologic processes that may simulate sports injuries can aid clinicians in the prompt diagnosis and clinical decision making of these rare tumors.

Bursal synovial chondromatosis formation following osteochondroma resection.

Osteochondroma is a common tumor of the bone and can be complicated by adventitial bursa formation and malignant transformation of the cartilaginous cap. Synovial chondromatosis formation within these bursae is extremely rare and can be confused with malignant transformation of the osteochondroma cap to a chondrosarcoma. We describe a case of extra-articular synovial chondromatosis formation several years following osteochondroma resection. Cartilage nodule formation within the bursal synovial lining and proliferation of cartilage debris shed from the cartilaginous cap during surgery or biopsy are potential etiologies of this rare complication of osteochondromas.

Osteochondroma of the hip with adjacent bursal chondromatosis.

It is well established that irregular bursae can form adjacent to an osteochondroma (bursa exostotica) as a result of mechanical irritation and that these bursae can be complicated by inflammation, hemorrhage, or infection. Bursal chondromatosis is a rare complication, with only seven published cases in the literature according to our searches. We present the case of a 53-year-old female who presented with slowly progressive left hip/thigh pain and was found to have an osteochondroma arising from the lesser trochanter with numerous ossified bodies in the adjacent soft tissues. MRI demonstrated osteochondral bodies in a fluid-filled bursa adjacent to the osteochondroma, with several of the bodies noted to be fairly displaced from the osteochondroma cartilaginous cap. At surgery, the osteochondroma was removed and numerous bodies of varying sizes were excised, some of which were noted to be adherent to the bursal lining and others that were separated/distant from the cartilage cap. The question arises as to whether this process represents bursal chondromatosis resulting from benign neoplasia of cells lining the abnormal bursa, "cartilage shedding" from the osteochondromatous cap, or both. The purpose in presenting this case is to introduce a rare complication of an osteochondroma, demonstrate that soft tissue calcification and osteochondral densities displaced from an underlying osteochondroma are not always the result of sarcomatous degeneration, and provide support for the theory that cells lining a bursa in a nonphysiologic location can undergo benign neoplasia with subsequent formation of osteochondral bodies.

Secondary synovial osteochondromatosis of the ankle in a child.

We describe a case of a large intra-articular ossifying mass of the ankle joint in a 12-year-old boy who sustained a severe ankle twisting injury at 6 years of age. The mass is presumed to be the result of secondary synovial osteochondromatosis originated from a fractured osteochondral fragment of the medial tubercle of the posterior process of the talus. The mass could be differentiated from os trigonum syndrome, Trevor disease and primary synovial osteochondromatosis based on its location, size and radiologic and histological features.

Huge tophaceous pseudogout associated with tenosynovial chondromatosis arising from flexor digitorum tendon sheaths of the foot: a case report.

Synovial chondromatosis (SC) is a benign proliferative process of synovial tissue creating multiple cartilaginous nodules in joints. It most commonly occurs in the large joints of the knee, hip, and shoulder, uncommonly in the small joints of the hand and foot, and only rarely in the tenosynovial membrane of tendon sheath, termed tenosynovial chondromatosis (TC). Unlike SC, TC predisposes to the foot or hand. The rarity and unfamiliarity of imagers with TC, as well as the variability of its histologic features often lead to an erroneous diagnosis of extraskeletal chondroma or even chondrosarcoma as in the present case. Calcium pyrophosphate dehydrate (CPPD) crystals are usually deposited in the articular cartilage or periarticular structures such as synovium and capsule, and rarely in other soft tissue structures including bursa, tendon, subcutaneous tissue, and dura mater. CPPD crystals may also be deposited in extraskeletal chondroma and SC. We present an exceptionally rare case of huge tophaceous pseudogout associated with TC that is considered to arise from the flexor digitorum longus tendon sheaths of the foot, initially mistaken for a chondrosarcoma.

Severe ulnar nerve palsy caused by synovial chondromatosis arising from the pisotriquetral joint: a case report and review of literature.

We report here the unique case of 60-year-old man with severe ulnar nerve palsy caused by synovial chondromatosis arising from the pisotriquetral joint. At operation, the tumor entrapped the ulnar nerve proximal to the Guyon canal so that it was severely paralyzed. The ulnar neurovascular bundle could be separated safely under the microscope. To our knowledge, this type of severe neuropathy has not been reported before. Although synovial chondromatosis associated with peripheral nerve neuropathy is extremely rare, we should be aware of the existence of this type of compression neuropathy in the upper limb.

Synovial chondromatosis of the upper extremity.

Synovial chondromatosis is a rare, benign, proliferative cartilaginous lesion arising from the synovial tissue or bursal lining of or near joints. This disease process can be classified into intra-articular and extra-articular, or tenosynovial, subtypes. Diagnosis can often be delayed due to the rarity of the disease and its nonspecific symptoms of pain, reduced range of motion, or swelling. This article reviews the literature and describes the classification, clinical course, demographics, diagnosis, histology, and treatment of synovial chondromatosis and tenosynovial chondromatosis in the upper extremity.

Giant extra-articular synovial osteochondromatosis of the sinus tarsi: a case report.

A 32-year-old male presented with painful swelling of the sinus tarsi that occurred during daily activities. Diagnostic imaging suggested the presence of a large synovial osteochondromatosis that blocked subtalar motion with deformity of the adjacent bone. The large bony mass was excised, and normal subtalar motion was achieved.

Synovial osteochondromatosis with malignant transformation to chondrosarcoma in a dog.

A 4.5-year-old intact male Labrador Retriever dog had a 1-month history of right forelimb lameness with painful swelling of the elbow. The radiographic findings of increased synovial mass with mineralized opacities and the gross and histologic findings in the synovial biopsy specimens were consistent with a diagnosis of primary (idiopathic) synovial osteochondromatosis. Twenty months after initial presentation, based on progression of clinical signs and radiographic evidence of marked bone lysis in the distal aspect of the humerus and proximal aspects of the radius and ulna, the affected leg was amputated. The histologic diagnosis was chondrosarcoma with fibroblastic differentiation and bone lysis. The chondrosarcoma was interpreted as malignant transformation of primary synovial osteochondromatosis.