Intra-articular nodular fasciitis

Two case reports of intra-articular nodular fasciitis of the knee confirmed by MYH9-USP6 gene fusion expression

AIM

To describe two cases of intra-articular nodular fasciitis (NF) which developed within the knee joint and were associated with the expression of the MYH9-USP6 gene fusion.

PATIENTS AND METHODS

Two women, 30 and 56 years of age, with no history of joint disease or knee joint trauma, are presented in our cases. We report these cases describing the clinical presentation, assessment, histopathological examination, gene expression, and clinical management.

RESULTS

Both patients presented with knee pain and limitation in the range of flexion. We diagnosed our two cases as intraarticular nodular fasciitis based on histological findings and by the detection of the MYH9-USP6 gene fusion. The transcript of MYH9-USP6 gene fusion was identified by RT-PCR and direct sequencing in both cases.

CONCLUSION

We report the first cases of intra-articular NF involving the knee joint, with identification of a MYH9-USP6 gene fusion by RT-PCR. NF should be considered in the differential diagnosis of intra-articular lesions.

Intraarticular nodular fasciitis-detection of USP6 gene fusions in three cases by targeted RNA sequencing

Intraarticular nodular fasciitis arising in the joint synovium is an uncommon lesion. Most cases have been reported in the knee and rarely in other joints. A USP6 gene fusion has so far been documented in only four cases of intraarticular nodular fasciitis, three were located in the knee and one in the proximal interphalangeal joint. In all three cases located in the knee, MYH9 was detected as a USP6 fusion partner. We analysed three cases of intraarticular nodular fasciitis for the presence of USP6 fusion by targeted RNA sequencing. Two cases were located in the hip (a 25-year-old female and 48-year-old male) and one in the shoulder (a 38-year-old male). We detected a MYH9-USP6 fusion in the two hip cases and a COL1A1-USP6 fusion in the shoulder case. Our findings provide additional evidence that intraarticular nodular fasciitis is a form of nodular fasciitis arising in the joint synovium, harbouring a USP6 fusion. Although a MYH9-USP6 fusion seems to predominate in intraarticular nodular fasciitis, other fusion partners of the USP6 gene may also be involved. Detection of a USP6 fusion by targeted RNA sequencing may assist in confirming the diagnosis in selected cases.

Surgery on aggressive fibroma of the posterior compartment of the knee: A case report

INTRODUCTION

Fibroma is a benign tumor. More than 99% fibroma arises from tendon sheaths or tendons. Aggressive Fibroma at posterior compartment knee is a rare case. This report presents one case of fibroma at posterior compartment of the knee with the treatment.

CASE REPORT

A boy with 4-year history of knee discomfort and lump at posterior knee joint, no history of infection and trauma. Physical examination revealed a mass (10 × 9 × 7 cm) with limited Range of Motion extension 30°, flexion 70°. MRI revealed a soft tissue mass at posterior knee compartment. Histologic examination showed a circumscribed and lobulated hypo cellular mass containing spindle cells diagnosed as aggressive fibroma. The patient underwent popliteal resection. An ellipse incision was made 2 cm margin of skin around the biopsy site. Fasciocutaneous flaps were created and retracted to expose the posterior compartment. The tumor had a partial well-defined capsule, popliteal artery and vein embedded and pressing the sciatic nerve. The tumor and enveloping muscles were elevated from the base of the compartment. The sciatic nerve was preserved with epineurotomy. The popliteal artery was reconstructed with saphenous veins graft. After the tumor was resected, the heads of gastrocnemius were sutured to each other and to the hamstring muscles to cover popliteal space. After one year postoperative, there was a good vascularization, no recurrence and neurological deficit with Musculoskeletal Tumour Society Scoring System 80%.

CONCLUSION

One year postoperative with popliteal resection surgery yields a good result. A follow-up is needed for risk of recurrence and malignancy.

A case of intra-articular fasciitis in the elbow joint

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Intra-nodular fasciitis is very rare and there are only two reported cases of intra-articular nodular fasciitis in the elbow joint.

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It is difficult to diagnose preoperatively, so a clear diagnosis can be obtained only after excisional biopsy.

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As local recurrence has not occurred in previously reported cases, we think that arthroscopic resection is suitable for treatment of this disease.

Introduction

Nodular fasciitis is a benign myofibroblastic proliferation arising from the fascia. Until now, there have been only two reported cases of intra-articular nodular fasciitis in the elbow joint.

Presentation of case

We report a case of a 19-year-old woman with a 3-month history of pain in the left elbow. Contrast-enhanced T1-weighted magnetic resonance imaging (MRI) showed an intra-articular lobulated mass on the anterior portion of the elbow joint, with accompanying effusion. The patient subsequently underwent arthroscopic excision of the mass. Histologically, intra-articular nodular fasciitis was the final diagnosis. At the most recent follow-up, 20 months after surgery, the patient had no subjective symptoms, including pain. The final MRI findings showed no tumor recurrence.

Discussion

As nodular fasciitis is not generally known to arise within a joint, the occurrence at such anatomical locations may lead to a misdiagnosis. Intra-articular nodular fasciitis is rarely encountered, and therefore, is not usually considered during the clinical investigation of joint symptoms.

Conclusion

Preoperative diagnosis was difficult in this case because of nonspecific preoperative clinical findings. Although histological examination is necessary to establish a diagnosis, we recommend that intra-articular nodular fasciitis should be included in the differential diagnosis of intra-articular mass lesions.

Intra-articular nodular fasciitis: a rare lesion case report and an updated review of the literature

BACKGROUND

Nodular fasciitis is a benign proliferation of myofibroblasts that usually arises in subcutaneous tissues of the trunk, neck, head, and upper extremities of young adults. It is not reported to arise in the joints.

CASE PRESENTATION

In this report, we describe a rare case where nodular fasciitis occurred in an intra-articular location in the right knee of a 20-year-old man. The patient presented with 3-months' duration of knee pain without history of trauma to the extremity. Physical examination revealed pain, joint effusion, and limited range of motion (ROM) of the affected knee. Magnetic resonance imaging (MRI) showed a 2.5 × 2 × 1 cm lesion in front of the posterior cruciate ligament. Arthroscopically, the soft tissue mass was removed and pathologically diagnosed as a rare, benign, intra-articular nodular fasciitis. Symptoms resolved 1 month after the operation and no recurrence was found at the 6 months follow-up.

CONCLUSION

The present paper describes detailed characteristics of intra-articular nodular fasciitis and provides an updated comprehensive summary of 21 prior case reports.

Intra-articular nodular fasciitis of the proximal interphalangeal joint of a finger: A case report

Nodular fasciitis is a benign reactive lesion, often mistaken for a soft-tissue sarcoma in clinical practice. Involvement of the finger is rare, and a finger joint even rarer. We report on the clinical, radiological and histological features of intra-articular nodular fasciitis in a 52-year-old man, originating from the proximal interphalangeal joint of the right ring finger, with cortical erosion of adjacent bone. The discussion is focused on the tumor diagnosis and therapeutic approach, the differential diagnosis and the importance of immunohistochemical staining to establish the final diagnosis.

Intra-articular nodular fasciitis: an unexpected diagnosis for a joint lesion: a case report

Pathological lesions in and around a joint can arise from underlying dermis, subcutis, deep muscle, bone or synovium. Clinical presentation can include joint pain, joint swelling, palpable masses and mechanical restriction. Whilst giant cell tumour of tendon sheath, pigmented villonodular synovitis, synovial chondromatosis, lipoma arborescens, juxta articular myxomas and inflammatory arthritis are the better-known conditions of the joint. Intra-articular nodular fasciitis, on the other hand, is less well recognized both clinically and radiologically. It is rarely seen in routine practice and is only described in case reports in the literature. Due to the non-specific clinical and radiological findings as well as the unfamiliarity with the entity, the diagnosis of intra-articular nodular fasciitis is usually clinched only after histological examination. We present a case of intra-articular nodular fasciitis arising in the knee joint which was not suspected clinically or radiologically.

MRI characteristics of nodular fasciitis of the musculoskeletal system

OBJECTIVE

To evaluate MRI imaging appearances of nodular fasciitis in a pathologic-proven series of 29 patients.

MATERIALS AND METHODS

Review of the orthopedic oncology and pathology databases yielded 51 cases of histologically proven nodular fasciitis. MR imaging was available in 29 patients. Three musculoskeletal radiologists retrospectively reviewed all cases in consensus. Imaging features evaluated included location in the body, size, compartmental localization, relationship to fascia, signal characteristics, enhancement pattern, transcompartmental extension, and osseous and intra-articular involvement.

RESULTS

There were 15 male and 14 female patients. Mean age was 33 years (range, 16-59 years). Lesions ranged in size from 1.6 to 9 cm with 84 % of lesions measuring less than 4 cm. Twenty-three lesions were located in the upper arm or shoulder girdle. Nine lesions were subcutaneous in location, nine were intra-muscular, and 11 were inter-muscular. Lesions were consistently ovoid in shape with broad fascial contact. They exhibited internal homogenous low T1 and heterogeneous intermediate T2 signal with surrounding edema and slightly inhomogeneous enhancement. Twelve lesions exhibited central non-enhancing areas. Trans-compartmental spread was demonstrated in nine lesions. Osseous changes were seen in five cases and included extrinsic cortical saucerization, medullary edema, and transcortical osseous invasion. Two lesions demonstrated intra-articular extension.

CONCLUSIONS

MR imaging features of nodular fasciitis are generally non-specific and can be mistaken for a soft tissue sarcoma. This series, the largest MRI series of musculoskeletal cases in the literature, confirms the predilection of nodular fasciitis for the upper extremity in young adults but also demonstrates that aggressive imaging features such as transcompartmental spread, and osseous and intra-articular involvement may be seen in association with this benign soft tissue lesion.

Intra-articular nodular fasciitis of the knee in a 4-year-old girl: a case report and review of the literature

Nodular fasciitis is a benign, proliferative lesion of myofibroblasts developed from the fascia. It arises commonly in the upper extremities of adults and in the head and neck region of infants and children. Involvement of the knee is exceedingly rare. We report a case of a 4-year-old girl with a knee mass, causing limitation of knee flexion and pain. Arthroscopic examination was performed followed by arthrotomy and tumor excision. Pathologic findings revealed clusters of spindle cells with arrangement of storiform pattern in a loosely textured mucoid matrix. To the best of our knowledge, this is the youngest patient associated with articular nodular fasciitis in the knee joint.

Intraarticular nodular fasciitis of the hip

Intraarticular nodular fasciitis is a rare lesion that has only recently been recognised. We present a case of intraarticular nodular fasciitis of the hip joint in a 25-year-old woman, who presented with a 9-month-history of right groin pain and a decreased range of right hip motion. A polypoid mass, composed of five nodules attached to the synovial membrane of the distal peripheral compartment of the hip was removed arthroscopically, together with two detached nodules. Histopathological examination revealed a myofibroblastic proliferation typical of nodular fasciitis. Complete resolution of symptoms and restoration of function was achieved, without recurrence 2 years after removal of the lesion. To the best of our knowledge, this is the first case of intraarticular nodular fasciitis of the hip, presenting a new indication for arthroscopic treatment.

Intra-articular nodular fasciitis of the shoulder: a case report and review of the literature

Nodular fasciitis is a benign proliferation of myofibroblasts usually arising adjacent to the fascia. In this report, we describe a rare case in which nodular fasciitis occurred in an intra-articular location in the shoulder of a 26-year-old man. The mass developed in the subscapularis recess of the shoulder and histological evaluation showed a myofibroblastic proliferation. MRI findings of intra-articular nodular fasciitis are discussed along with a review of previous reports.

Intraarticular nodular fasciitis causing limitation of knee extension: a case report

We report a patient with intraarticular nodular fasciitis who developed mechanical symptoms in the knee, limiting knee extension. A 24 year-old man presented with mechanical restriction of extension and pain at maximum extension. MRI revealed an intraarticular mass within the knee joint. The mass was excised arthroscopically. Histological examination of the excised tissue led to a diagnosis of nodular fasciitis. Pain and limitation of motion of the knee disappeared from one day after surgery. No recurrence was found after 1 year. Intraarticular nodular fasciitis is rare, and although this lesion within the knee has been reported previously, it has not been associated with mechanical symptoms. This case indicates that intra-articular fasciitis should be considered in the differential diagnosis of a patient presenting with mechanical limitation of knee extension and a mass lesion inside the knee joint.

Intraarticular fibroma of the posterior compartment in the knee. A case report

Posterior knee discomfort and recurrent effusion of the left knee occurred in a 49-year-old man without a history of specific trauma. Magnetic Resonance Imaging (MRI) and an arthroscopic examination revealed a soft tissue mass arising from the posterolateral capsule. The microscopic diagnosis was a fibroma, which is a rare entity in this location. To the best of our knowledge, only four cases of fibroma in the knee have been reported. It was reported that more than 99% of fibromas arise from tendon sheaths or tendons. They sometimes present a diagnostic problem due to their relative rarity in this location and obscure histological features. Fibroma should be included in a differential diagnosis of a soft tissue tumor arising from the knee joint. However, an arthroscopic excision was curative in our case.

Intraarticular Nodular Fasciitis-A Rare Lesion

Nodular fasciitis is a benign myofibroblastic proliferation with a predilection for the subcutaneous tissues of the upper extremities, trunk, and head and neck of young adults. Nodular fasciitis is not generally recognized to arise within joints. In this study, the clinicopathologic and immunohistochemical features of 10 cases of intraarticular nodular fasciitis are described. Six patients were female and 4 were male, with a median age of 33 years (range, 9-50 years). Lesional size ranged from 2 to 4 cm (median, 2.6 cm). Seven tumors arose in the knee, 2 in the hand, and 1 in the ankle. Most patients complained of joint pain; 4 presented with a palpable mass. Only 1 patient reported antecedent trauma. The duration of symptoms prior to surgery ranged from 2 months to 1 year (median, 6 months). The clinical differential diagnoses included giant cell tumor of tendon sheath, pigmented villonodular synovitis, synovial chondromatosis, inflammatory arthritis, and lymphoma. Grossly, the lesions were solid, nodular, rubbery, or firm masses. Histologically, all tumors were circumscribed but unencapsulated and showed typical features of nodular fasciitis, being composed of cytologically bland plump spindle cells arranged in short, intersecting bundles within a variably loose myxoid to collagenous stroma, containing extravasated red blood cells and scattered lymphocytes. Five lesions showed prominent stromal hyalinization, in 2 cases keloidal in appearance. In 4 cases, the tissue at the periphery of the lesion showed hemosiderin deposition. By immunohistochemistry, all tumors examined were positive for SMA, 1 was positive for desmin, and all were negative for caldesmon and S-100 protein; none showed nuclear staining for beta-catenin. Clinical follow-up information was available for 5 patients, ranging from 2 to 86 months. No lesion recurred. In summary, intraarticular nodular fasciitis occurs most commonly in the knees of young adults, and often appears to have a somewhat longer preoperative duration than typical subcutaneous or intramuscular nodular fasciitis. Intraarticular lesions show morphologic features similar to other cases of nodular fasciitis, with the exception that stromal hyalinization and adjacent hemosiderin deposition are common, likely attributable to frictional trauma in this location.

Fasciitis-like proliferation in the knee joint

We describe the case of fasciitis-like proliferation in the knee joint in a 52-year-old man. The polypoid lesion developed from the synovial joint capsule around the quadriceps tendon and was impinging on the patellofemoral joint. Histologic and immunohistochemical studies revealed a myofibroblastic proliferation similar to nodular fasciitis. Until now, only 3 other cases have been reported in the English and Japanese language literature.