Synovial Mass Research Articles

A 55-year-old Man with Painless Joint Swelling

A 55-year-old man presented with swelling of left knee for the past one month. He also complained of episodes of joint locking. There was no history of pain, fever or trauma. Physical examination revealed localized increase in temperature of the skin, a large joint effusion, and decreased range of motion. His total leukocyte count was normal; ESR was raised to 48 mm in the first hour. Antero-posterior and lateral radiograph of the knee revealed large joint effusion with no bony abnormality. Subsequent magnetic resonance imaging (MRI) performed revealed joint effusion with lobulated enhancing synovial masses around the knee joint. The masses appeared low signal on T1 weighted (Fig. 1), T2-weighted and Proton density image (Fig. 2a). Blooming effect with marked loss of signal was seen on GRE-DESS image (Fig. 3). FNAC and joint aspiration was hemorrhagic. Synovial biopsy was performed and revealed villi and nodule with extensive hemosiderin deposition and abundant multinucleated giant cells. Figure 1 Sagittal T1-weighted MRI shows lobulated low signal synovial masses in knee joint and popliteal bursa with erosion of tibial condyle. Figures 2a and 2b Sagittal and axial proton density (PD) weighted MRI shows joint effusion with lobulated and frond-like heterogeneous hypointense lesion within the joint and bursa. Figure 3 Shows marked loss of signal with Blooming effect on GRE-DESS image. Questions What are the differential diagnoses and diagnosis? What is the management for this case and the role of MRI in it?' Answers The differential diagnoses of hypointense synovial masses on T2 weighted MRI are; pigmented villonodular synovitis (PVNS), synovial osteochondromatosis, hemophilic arthropathy, and amyloid deposition. The diagnosis was PVNS made by characteristic MRI and histopathological features. Complete synovectomy is the most common treatment; however, it is often not possible in large joints because of the complexity of the joint structure. Recurrence rates are high. Other treatment options include radiation therapy, pharmaceutical modulation of the disease, or a combination of these approaches. MRI has a very important role by demonstrating the characteristic finding and allows for the preoperative non-invasive diagnosis.

Synovial chondrosarcoma arising from synovial chondromatosis of the knee

We report the case of a 51-year-old woman who had suffered from right knee pain and stiffness for 40 years. Her symptoms had gradually worsened over the past 5 years. One year previously, when she first visited our clinic, plain radiographs and CT scan images had revealed synovial chondromatosis over the right knee. At the current admission, follow-up MRI showed synovial masses around the knee and worsening of endosteal cortical scalloping in the patella, femoral condyle, and tibial plateau. After diagnosis on the basis of frozen sections, the patient had total excision of the lesions and total knee athroplasty. Histological examination revealed synovial chondromatosis in the joint cavity and grade 1 chondrosarcoma invasion into the adjacent bone. In long-standing synovial chondromatosis, presentation with aggravated symptoms and deterioration on imaging findings should alert clinicians to the potential for malignant change.

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.

Baker’s Cyst Rupture May Mimics Deep Vein Thrombosis

Copyright: © 2012 Angoules AG. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Αlthough the first report on a popliteal cyst was originally reported by Adams in 1840 [1] these cysts were named thirty-seven years later, after Wiliam Baker published his famous paper [2]. Popliteal or Baker’s cysts are abnormal synovial fluid-filled masses located in the popliteal fossa and almost always result in chronic knee joint effusion. The cyst may be a herniation of the gastrocnemius or semimembranosus bursa through the fibrous layer of the joint capsule into the popliteal fossa, communicating with the synovial cavity of the knee joint by a narrow stalk [3]. This communication between the knee joint and one of the popliteal bursae in up to 40% of normal knees has been described [4]. In a recent ultrasonographic evaluation their size varies from 1.4–6.2 cm [5] .

Synovial Hemangioma in a 2 Year Old Mimicking Synovial Osteochondromatosis

We describe a rare synovial mass arising from the elbow of a 2 year old female. It was growing slowly for three months and there was no history of trauma or fever. Plain radiographs showed a soft tissue mass around the elbow with scattered nodular intraarticular calcifications. Ultrasound and MRI confirmed the synovial location of the mass and again showed the multiple calcifications, some of which suggested intraarticular loose bodies. The imaging findings were thought to represent synovial osteochondromatosis but subsequent biopsy revealed a synovial hemangioma and it is for this reason that we present our case.

Cubital Tunnel Syndrome Caused by Amyloid Elbow Arthropathy in Long-term Hemodialysis Patients: Report of 4 Cases

Carpal tunnel syndrome occurs frequently in long-term hemodialysis patients. However, the literature contains few detailed reports of other nerve entrapment syndromes of the upper extremity in these patients. We encountered 4 cases in which cubital tunnel syndrome occurred in long-term hemodialysis patients. In all cases, a hypertrophic synovial mass projecting from the humeroulnar joint compressed the ulnar nerve, and Congo red staining revealed that the mass contained amyloid deposition. Synovial proliferation resulting from amyloid arthropathy of the elbow joint appears to be the primary cause of this disease.

Bilateral knee lipoma arborescence diagnosed by ultrasound

Dear Editor, A 57-year-old Hispanic woman with no significant past medical history, presented to our clinic with a 5-year history of bilateral knee pain and swelling for which she had tried naproxen without much relief. Physical examination revealed a moderate effusion in the right supra-patellar region with a limited range of motion from 0° up to 100°. The left knee effusion was milder and range of motion was preserved. Laboratory tests demonstrated a normal leukocyte count, C-reactive protein and erythrocyte sedimentation rate. Furthermore, synovial fluid analysis was non-inflammatory without any crystals. Rheumatoid factor (RF) was 31 IU/mL (normal < 13.9) but anti-cyclic citrulinated protein (anti-CCP) was negative. Radiographs of right knee demonstrated a moderate knee effusion without erosions. Radiographs of bilateral hands demonstrated joint space narrowing and osteophytes along both the first metacarpophalangeal joints consistent with osteoarthritis. Ultrasound of bilateral knees revealed a villous hyperechoic fatty proliferation with clear frond-like morphology inside the pouch, consistent with lipoma arborescens, more prominent in the right knee (Fig. 1). MRI of the right knee demonstrated suprapatellar joint effusion and frond-like projections of hypertrophied synovium (Fig. 2). Although positive for RF, the patient did not have any signs of active synovitis and hence was referred to orthopedic surgery for synovectomy. Longitudinal view, 7.5–12 MHz ultrasound image of both knees over suprapatella recess demonstrates a large effusion and villous hyper-echoic fatty synovial proliferation with clearly frond-like morphology inside the pouch. Sagittal T2-weighted image with fat saturation of the knee demonstrates a large suprapatellar joint effusion. Frond-like projections of hypertrophied synovium extend into the high-signal joint fluid. The signal intensity of the frond-like projections is identical to the subcutaneous fat. Discrete intra-articular solid lipomas are very rare; the more common finding is lipoma arborescens which represents a diffuse fatty lesion of the joint.1 A characteristic gross feature is an increased level of mature fat cells, which proliferate under the synovium, producing excess pressure on the synovial lining which leads to bulges which appear as multiple villi-like morphologies.2 At the cellular level, there are sheets of mature adipocytes, which are mixed with vasculature and separated by fibrous septae.2 The main differential diagnosis to consider in this scenario is pigmented villonodular synovitis. On ultrasound, pigmented villonodular synovitis (PVNS) presents as a well-delinated hypo-echoic mass inside the Hoffa fat pad (infra-patellar fat pad); in contrast lipomatosis arborescence presents as a hyperechoic frond-like lesion. On MRI PVNS exhibits low signal on both T1- and T2-weighted sequences due to hemosiderine deposites in the synovium. These lesions manifest various clinical symptoms depending on location and extent of fat proliferation. However, chronic intermittent effusions, edema and limited range of motion in the affected joint are common manifestations.1, 2 Although the most common location for this entity is in the suprapatellar region of the knee, there have been case reports of a multitude of other joints affected, such as wrists, hips, ankles, glenohumeral joints and tendon sheaths.2-5 Although there have been multiple lipomatosis arborescens cases which are classified as secondary to an underlying pathology such as RA, DJD or trauma, there are also cases without any underlying reactive process.1, 6 Hence, the underlying trigger for the proliferation of these fat cells under the synovial lining is yet to be elucidated. Radiographic features include a soft tissue mass within the synovium and occasionally along with degenerative findings.1, 7 On MRI the villi formed by the synovial mass appear as frond-like structures and the signal intensity of the villi resembles fat.1, 5, 7 Characteristic sonographic findings demonstrate an effusion along with a hyper-echoic synovial mass with villi, which demonstrate wave-like motility upon compression via ultrasound probe.7 We believe this case is among the few unique cases of lipomatosis arborescens found to occur in a bilateral distribution. Furthermore, this is the first time that this entity has been diagnosed primarily via ultrasound and only confirmed by MRI as a secondary imaging modality. When considering lipomatosis arborescens in the differential diagnosis, utilizing ultrasound as the first diagnostic imaging modality, is a quick, inexpensive and reliable method to make the diagnosis, given unique and characteristic sonographic features of this entity.

Hypertrophic Synovial Mass Resulting in C8 Radiculopathy -Case Report-

A 58-year-old man presented with a hypertrophic synovial mass manifesting as left C8 radiculopathy. Computed tomography revealed hypertrophic changes in the left C7-T1 facet joint and widening of the interarticular space. Magnetic resonance imaging showed left C7-T1 foraminal stenosis attributable to a periarticular mass enhanced with gadolinium. Decompression surgery of the left C8 nerve root was performed. During left C7-T1 facetectomy we detected inflamed soft tissue occupying the interarticular space with extension toward the intervertebral foramen. The mass markedly compressed the left C8 nerve root and was gross totally removed. The histological diagnosis was proliferated fibrous connective tissue compatible with hypertrophic synovial tissue. Postoperatively, his neurological condition improved remarkably. The surgical and pathological findings in our patient indicate that this clinical condition is important in the differential diagnosis in adult patients presenting with cervical radiculopathy.

Gene Expression Studies to Investigate Disease Mechanisms in Rheumatoid Arthritis: Does Angiogenesis Play a Role?

Gene expression studies represent a new and challenging approach that allows molecular dissection of complex diseases such as rheumatoid arthritis (RA). Optimally, gene analysis should be conducted in isolated populations of cells so that the differential gene expression may be directly correlated with transcription of genes. RA fibroblasts constitute the majority of the expanding synovial cell mass in the RA joint, and alterations in their phenotype are likely to be important in the pathogenic process. However, RA involves many cell types from tissues adjacent to the synovium and the important cell types are not known. Analysis of gene expression profiles by processing a complex tissue such as whole paws can provide useful information about dysregulated genes, not only in the synoviocytes but also in other, neighbouring cells (monocytes, osteocytes and chondrocytes) that may contribute to disease pathology. This review will focus on the use of gene expression studies, both in isolated cells and in whole tissue, as a means of studying the molecular mechanisms involved particularly in the angiogenic process in RA. In particular, we will focus on synovial angiogenesis, since the synovial vascular density is altered in RA. This will provide an increased surface area for inflammatory cell trafficking, as well as delivering nutrients and oxygen to the proliferating synovial cells. Therapeutic approaches targeting angiogenic factors such as vascular endothelial growth factor (VEGF), which is increased in RA, have already shown some clinical success in oncology, and in mouse models of arthritis.

Outcome of 17 pigmented villonodular synovitis (PVNS) of the Knee at 6 years mean follow-up

Between January 1950 and December 2000, 16 patients were identified from Scottish Bone Tumour Registry with 17 histologically proven pigmented villonodular synovitis (PVNS) of the knee. The mean follow-up was 6 years (range, 1–14 years). A knee swelling of chronic duration with dull ache was the common presenting symptom. The mean duration of symptoms prior to presentation was 25 months (1–108 months), however it was much less (mean, 7 months) in four patients with a history of trauma. The mean age was 33 years (range, 16–58 years) with a slight male predominance. The lesion was predominantly anterior in nine patients, posterior in four, anterolateral in two, and medial and lateral in one each. Three patients (four knees) had localised disease and 13 diffuse. Anteroposterior and lateral radiographs of the knee revealed normal findings in 11 patients, features of gonarthrosis in four and a large suprapatellar loose body in one patient (both knees). Open (incisional-eight, excisional-eight) biopsy was carried out in all and all were histologically confirmed as PVNS. Removal of a localised synovial mass or loose body with surrounding partial synovectomy (four) was carried out for the localised variety, whilst open partial (three) or total (radical) synovectomy (10) was performed in all cases of diffuse PVNS. Three of seventeen knees had a recurrence, noted at 4, 6 and 8 years postoperatively (0% — localised, 23% — diffuse variety). A total (radical) synovectomy should be considered in diffuse PVNS in order to obtain optimal outcome.

Synovial chondromatosis of the posterior cruciate ligament managed by a posterior–posterior triangulation technique

Various causes have been reported for cystic lesions arising from the cruciate ligaments. We present a case of synovial chondromatosis that involved the posterior cruciate ligament and was treated by an arthroscopic posterior-posterior triangulation method. We recommend that synovial chondromatosis be considered in the differential diagnosis of cystic lesions of the cruciate ligaments. Lesions involving the posterior aspect of the posterior cruciate ligament, as in the presented case, can be accessed via the standard anterior arthroscopic portals. However, scattered synovial chondromatosis masses located in the posterolateral compartment are difficult to access via anterior portals. We suggest that the arthroscopic posterior-posterior triangulation technique may be useful for the management of such cases.

A newly recognized polyosteolysis/hyperostosis syndrome

We report a newly recognized bone disorder consisting of polyostotic expansile osteolysis affecting long bones and iliac bones; hyperostosis of the skull, thoracic cage, and medial portion of both clavicles; pectus carinatum; gigantiform synovial masses of the elbows and knees; atrial septal defect; cardiomegaly; unilateral cryptorchidism; and mental deficiency. Affected bones can be grouped into four general types of skeletal pathology: (1) expansile osteolysis, (2) osteolysis without expansion, (3) expansion without osteolysis, and (4) hyperostosis. Some bones remained unaffected. We have named the condition "polyosteolysis/hyperostosis syndrome." It is clearly at variance with any previously reported bone disorder, including familial expansile osteolysis, juvenile Paget disease, and McCune-Albright syndrome (and polyostotic fibrous dysplasia). Because our patient shared some features in common with juvenile Paget disease, we thought that mutational analysis of TNFRSF11B was indicated, even though our patient had some manifestations not found in juvenile Paget disease. Direct sequencing failed to identify a TNFRSF11B mutation. Because the parents of our propositus were first cousins suggests that polyosteolysis/hyperostosis syndrome may possibly have autosomal recessive inheritance.

The popliteal cyst

A popliteal cyst, originally called Baker's cyst, is a synovial fluid-filled mass located in the popliteal fossa. The most common synovial popliteal cyst is considered to be a distension of the bursa located beneath the medial head of the gastrocnemius muscle. Usually, in an adult patient, an underlying intra-articular disorder is present. In children, the cyst can be isolated and the knee joint normal. The anatomy, etiopathogenesis, clinical presentation, differential diagnosis, imaging and treatment modalities of the popliteal cyst are presented. The authors try to answer some questions dealing with this condition. Is the cyst isolated, can it be treated as such, is its origin always well-defined and does surgical excision provide a permanent cure?

Synovial chondromatosis of the foot presenting with Lisfranc dislocation

Primary synovial chondromatosis is rare in the foot. We report a case of synovial chondromatosis affecting multiple sites of the foot and causing bone erosions in a 44-year-old woman. Radiographs demonstrated erosions of multiple metatarsals including the tarsometatarsal joints, resulting in Lisfranc tarsometatarsal dislocation. Magnetic resonance imaging showed the widespread synovial proliferation and soft tissue masses affecting the foot and helped in arriving at a differential diagnosis and plan for needle biopsy. Diagnosis was made initially by needle biopsy under computed tomography guidance and was subsequently confirmed by histopathological assessment of the surgically excised synovial masses. To our knowledge, multifocal synovial chondromatosis causing Lisfranc dislocation in the foot has not been reported previously.

Synovites réactionnelles : aspects en IRM et corrélations arthroscopiques

Objectives To evaluate MR imaging in detecting and characterizing secondary reactive synovitis and correlate the results with arthroscopy. Materials and methods Retrospective study of 10 patients referred for MR imaging and arthroscopy of the knee or shoulder. The diagnosis of reactive synovitis was confirmed by arthroscopy and pathological examination. Synovial thickening was graded at MRI as follows. Grade 0: normal; grade 1: diffuse synovial thickening; grade 2: nodular synovial hypertrophy; grade 3: pseudotumoral synovial mass. Results Synovitis was described at MRI in 8 cases. There were 2 false negative results on MR imaging for the knee. Synovitis was secondary to knee trauma and rotator cuff tear or surgery of the shoulder. On arthroscopy, all synovial lesions were detected and confirmed at pathology. Synovitis was not detected at MRI (grade 0) in 20% of cases. Synovitis appeared diffuse (grade 1) in 30%, nodular (grade 2) in 30% and pseudotumoral (grade 3) in 20%. Bony erosions were adjacent to synovial thickening in 5 cases. Conclusion Reactive synovitis can occur after trauma. MR imaging is useful in detecting and evaluating secondary reactive synovitis. Arthroscopy and synovial biopsy are necessary to exclude infectious or tumoral synovitis.

Arthroscopic treatment of solitary benign intra-articular lesions of the knee that cause mechanical symptoms

Most cases of knee locking and giving-way are caused by meniscal tears, loose bodies, or chondral lesions. Intra-articular benign tumors or tumor-like lesions can present with symptoms that resemble acute mechanical derangement. From a database of 2,200 arthroscopic interventions, 19 cases of intra-articular masses that presented with catching and locking symptoms in the knee were retrospectively analyzed. Case series. Our review revealed 33 patients with benign intra-articular masses in the knee joint. Nineteen of these individuals had sought medical attention for mechanical symptoms of catching or locking. The other 14 patients had a variety of symptoms including pain, swelling, and limitation of knee motion, but did not have mechanical symptoms. Age, sex, history of trauma, knee pain and effusion, medical illnesses, physical examination, arthroscopic findings, and pathologic findings were noted. The average age of the 6 male and 13 female patients was 37.5 years (range, 18 to 58 years). Preoperative magnetic resonance imaging confirmed the diagnosis in 7 cases and 12 cases were diagnosed during knee arthroscopy. The mean follow-up time after surgery was 52.5 months (range, 6 to 120 months). Pathologic examination of the lesions revealed 15 cases of localized pigmented villonodular synovitis (79%), 1 lipoma arborescens (5%), 1 pseudocyst (5%), and 2 nonspecific synovial masses (11%). None of the lesions showed malignant transformation. Solitary benign intra-articular lesions should be considered a rare cause of mechanical knee symptoms. Localized pigmented villonodular synovitis originating from the extensor mechanism or fat pad is the most common solitary intra-articular mass lesion in the knee and usually arises in the patellofemoral compartment. Recurrence has not occurred in our series, which includes 14 of 19 patients with greater than 24 months follow-up. Level IV.

MRI features of pigmented villonodular synovitis (PVNS).

The aim of this study was to characterize the magnetic resonance imaging (MRI) features of PVNS. The radiographs and MR images of 23 pathologically proven cases of PVNS were retrospectively reviewed, with emphasis on MR images. There were 9 males and 14 females, mean age 36 years. Of 23 cases, 9 occurred in the hip, 8 in the knee, 3 in the ankle, 2 in the elbow and 1 in the wrist. Typical MRI findings included variable extent of nodular synovial proliferation, from mild proliferation to extensive masses, joint effusion in all cases, and multiple bony erosions in 15. Owing to the tight joint space, bone involvement was frequently seen in the hip, ankle, elbow and wrist. Although the knee joint had a loose capsule, bone involvement was rarely seen. Hemosiderin is a magnetic material, its deposit on proliferative synovial tissue resulting in a spotty low signal or extensive low signal area within the proliferative synovial masses on T(1)- (T1WI) and T(2)-weighted (T2WI) images, best seen on fast field echo (FFE) sequence MRI images. Fat-suppressed sequences obscured the deposit. This is diagnostic of PVNS. The MRI features of PVNS include variable extent of synovial proliferation, joint effusion and erosion of bone, and in particular the deposit of hemosiderin within the synovial masses. The deposit of hemosiderin, appearing as a low signal area best seen on FFE sequence, is diagnostic for PVNS.

Tenoscopic examination and proximal annular ligament desmotomy for treatment of equine "complex" digital sheath tenosynovitis.

To determine the outcome of horses with "complex" digital tenosynovitis treated by tenoscopic proximal annular ligament desmotomy and resection of synovial masses or adhesions, or both, within the digital sheath. Retrospective evaluation. Twenty-five horses with a clinical and ultrasonographic diagnosis of palmar or plantar proximal annular ligament constriction and ultrasonographic evidence of synovial masses or adhesions within the digital tendon sheath. Each horse had tenoscopic surgery for annular ligament desmotomy combined with adhesiolysis and/or synovial mass resection. Mean follow-up time was 3.4 years. Spearman's rank correlation was used to assess the relationship between functional outcome or cosmetic results and preoperative variables including duration of clinical signs, digital sheath synovial fluid total protein concentration and nucleated cell count, thickness of the palmar or plantar proximal annular ligament (PAL), severity of adhesions, severity of synovial masses, degree of synovial distention, or limb affected. A total of 18 (72%) horses returned to athletic soundness, 4 were improved but not sound, and 3 were not improved. Cosmetic outcome was normal in 10 horses, improved but not normal in 12, and not improved in 3 horses. Cosmetic and functional outcome were significantly adversely affected by the duration of clinical signs and the severity of synovial masses. With appropriate tenoscopic surgical attention, horses with complex tenosynovitis syndrome characterized by synovial masses, adhesions, or both adhesions and masses, and PAL constriction, have a good prognosis for return to athletic soundness. Horses with PAL constriction and additional digital tendon sheath pathology such as adhesions and synovial masses have a 72% chance of returning to sound athletic performance, however 60% of horses retain some degree of cosmetic blemish in the affected limb. There is an inverse relationship between the duration of clinical signs and outcome, and therefore, prompt surgical attention is advised.

Expression of the activation antigen CD97 and its ligand CD55 in rheumatoid synovial tissue.

Fibroblast-like synoviocytes (FLS) express decay-accelerating factor (CD55) at high levels. Recently, it was found that CD55 is a specific cellular ligand for the 7-span transmembrane receptor CD97. The objective of this study was to define the expression of this receptor-ligand pair in synovial tissue (ST) to provide more insight into the interaction between FLS and surrounding cells. Antibodies against CD97 and CD55 were used for immunohistologic analysis of synovial biopsy specimens from 16 patients with rheumatoid arthritis (RA) and 15 patients with osteoarthritis (OA). In addition, an enzyme-linked immunosorbent assay system was used to determine the expression of soluble CD97 (sCD97) in synovial fluid (SF) from 30 patients with RA, 13 with OA, and 10 with reactive arthritis (ReA). In both RA and OA ST sections, strong expression of CD55 was confirmed on FLS in the intimal lining layer, where it was also found that all macrophages expressed CD97. The percentage of macrophages that expressed CD97 was lower in the synovial sublining (P = 0.005). The mean levels of sCD97 in SF were significantly higher in RA patients than in patients with OA or ReA (P < 0.0001). These results suggest that FLS are able to interact with macrophages via the CD97/CD55 receptor-ligand system. In this respect, the CD97/CD55 pair may account for the specific architecture of the intimal lining layer and may be of primary importance in maintaining and amplifying synovial inflammation. The specific increase in sCD97 levels in RA SF might be related to the presence of activated proteolytic systems or to the increase in synovial mass, rather than a consequence of local receptor-ligand interaction.

Starving the synovium: angiogenesis and inflammation in rheumatoid arthritis.

Starving the synovium: angiogenesis and inflammation in rheumatoid arthritis.