An intraarticular fibroma of the tendon sheath in the knee joint

Arthroscopic treatment for intra-articular fibroma of the tendon sheath in a teenager

An adolescent female patient presented with atraumatic left knee pain and limited flexion. MRI demonstrated evidence of a soft tissue lesion abutting the posterior cruciate ligament. Differential diagnosis included pigmented villonodular synovitis (PVNS) and fibroma of the tendon sheath (FTS). Following arthroscopic biopsy, histopathological evaluation confirmed FTS. The tumour was then excised via an arthroscopic approach. This case report provides a unique example of FTS abutting the cruciate ligaments in an uncommonly young female patient. It highlights the importance of including benign processes, such as FTS, in the differential with more aggressive-type diagnoses like PVNS. Furthermore, this case exemplifies an appropriate surgical indication for FTS. Finally, it emphasises the importance of communication and collaboration among orthopaedic subspecialists in providing safe and effective arthroscopic treatment of this unique tumour presentation.

Differential diagnosis of fibroma of tendon sheath and giant cell tumor of tendon sheath in the finger using signal intensity on T2 magnetic resonance imaging

BACKGROUND

The differential diagnosis of fibroma of tendon sheath (FTS) and giant cell tumor of tendon sheath (GCTTS) on the basis of clinical and radiographic characteristics remains difficult.

PURPOSE

To evaluate the quantitative measurement of signal intensity (SI) obtained by magnetic resonance imaging (MRI) for the differential diagnosis of FTS and GCTTS in just the finger.

MATERIAL AND METHODS

We retrospectively identified patients with FTS (n = 6) and GCTTS (n = 22) of the finger who were treated at our hospitals between April 2011 and August 2019. Two researchers independently reviewed the MRIs and measured the regions of interest (ROIs) in the tumor and flexor tendon from the same image. The SI ratio obtained for the tumor and tendon ROIs was measured and compared using receiver-operating characteristic curve analyses. Sensitivity and specificity analyses were performed.

RESULTS

The SI ratios (mean ± SD) of FTS and GCTTS were 1.83 ± 0.64 and 6.34 ± 3.16 for researcher 1 and 1.82 ± 0.60 and 6.10 ± 3.22 for researcher 2, respectively. The areas under the curve were 0.970 and 0.970 for researchers 1 and 2, respectively. The cut-off values of the SI ratio as determined by researchers 1 and 2 for differentiating FTS from GCTTS were 3.00 and 3.00, respectively (sensitivity = 95.5%, specificity = 100%).

CONCLUSIONS

The SI ratio is useful for differentiating FTS from GCTTS independent of a combination of tumor signal and shape.

Fibroma da bainha do tendão patelar: Um novo paradigma

Os autores apresentam um caso de um fibroma da bainha de tendão com localização intra-articular no joelho e origem na gordura infrapatelar. Esta localização específica é extremamente rara, sendo este o quarto caso descrito de uma entidade que raramente afeta grandes articulações. Para o seu diagnóstico aspetos clínicos, epidemiológicos e sobretudo achados imagiológicos da ressonância magnética são fundamentais. Neste caso o diagnóstico definitvo foi apenas estabelecido após estudo histológico da massa excisada por mini-artrotomia.

Fibroma of the patellar tendon sheath-a rare case in a young boy

Fibroma of the tendon sheath is a rare benign fibrocollagenous soft tissue tumor, arising predominantly from the synovium of tendon sheath. Fibromas occur most commonly in relation to the tendons of the fingers, hand, and the wrist. Fibromas related to large joints are rather rare and though amongst the large joints, the knee is a common site. Fibromas of the patellar tendon sheath, specifically, are very rare. To the best of our knowledge, only three cases of fibromas arising from the patellar tendon sheath have been reported in the relevant English medical literature. Herein we describe the fourth biopsy-proven case of fibroma of patellar tendon sheath in a 6-year-old boy.

Magnetic resonance imaging features of fibromas and giant cell tumors of the tendon sheath: differential diagnosis

PURPOSE

The clinical and imaging characteristics of fibromas of the tendon sheath (FTS) closely resemble those of giant cell tumors of the tendon sheath (GCTTS). We aimed to study MRI features of FTS and GCTTS to distinguish the two entities and improve their differential diagnosis.

MATERIALS AND METHODS

We retrospectively analyzed data from 18 patients (9 men, 9 women; age, 17-62 years) and 24 patients (13 men, 11 women; age, 15-67 years) treated between May 2011 and May 2016, with histologically confirmed FTS and GCTTS, respectively. Specific MRI features of the two groups were compared using the independent sample t tests and chi-square tests.

RESULTS

FTS exhibited round or oval shapes. Proton-weighted images (PDWI) showed heterogeneous hypointensity that appeared striped or disordered and was located in the lesion center. Enhanced scans demonstrated asymmetrical signal in the foci. GCTTS mostly exhibited a lobulated or casting mold pattern, with a hypointense ring on PDWI. The hypointense components appeared granular/flaky or separated, sometimes behaving as a uniform signal on PDWI. Significant differences in the following features were observed between the two groups: lesion morphology (p < 0.001); imaging features on PDWI, including whether the signal is homogeneous (p < 0.001); the presence of a hypointense ring (p = 0.006); the location and morphology of hypointensity (p < 0.001); bone absorption (p = 0.008); enhancing pattern (p = 0.008); and whether the tumor crossed the joint (p = 0.026).

CONCLUSIONS

FTS and GCTTS demonstrate distinctive MRI features, which can be used for differential diagnosis with sensitivities, specificities, and diagnostic accuracies of 83-100%, 29-79%, and 60-89%, respectively.

KEY POINTS

• Fibromas and giant cell tumors of the tendon sheath have distinct features on MRI, including differences in lesion morphology and intensity patterns, which can be used for differential diagnosis. • Among other signs, GCTTS are more uniform than FTS, and FTS have a striped or disordered pattern. • Tumors were classified with 90% accuracy into either FTS or GCTTS based on a combination of two features: homogenous signal and hypointensity shape on PDWI.

Peeled off water chestnut in the knee

Fibroma of tendon sheaths (FTS) is an uncommon soft tissue tumour which arises from the synovial sheath of tendons. We report a histologically proven case with intrarticular 'fibroma of tendon sheath' originating from the joint capsule of the knee, an even rarer entity, in a middle-aged female presenting with knee pain, swelling with limited range of motion. MRI and arthroscopy studies revealed an intra-articular mass originating from the synovial membrane with lobulated contours. Open excision was performed because of the large size of the mass, making it inaccessible arthroscopically. The patient is symptom free since the surgery done 15 months back.

Fibromas arising from the posterior cruciate ligament tendon sheath in the bilateral knee joints: Case report

Fibroma of tendon sheath in the intra-knee joint is a very rare and benign soft-tissue tumour which has been reported unilaterally in the various aged people. To help distinguish it from other similar kinds of lesions and symptoms including osteoarthritis, we report the oldest case of fibromas arising from the posterior cruciate ligament tendon sheath in the bilateral knee joints within one year of each other confirmed with magnetic resonance imaging (MRI) features, operative findings and histological examination.

Fibroma of tendon sheath around large joints: clinical characteristics and literature review

Background

Fibroma of tendon sheath (FTS) is a benign tumor arising from the synovium of the tendon sheath that occurs mostly around small joints such as the fingers, hands, and wrist. However, FTS rarely arises around a large joint (knee, shoulder, elbow, and ankle) with intra-articular or extra-articular involvement. The clinical characteristics of FTS arising around a large joint are unclear. An additional 3 cases of FTS arising around a large joint are presented. Furthermore, the published cases and the present cases are reviewed with respect to their clinical characteristics and imaging and histopathology findings.

Methods

The 43 reported cases including the present 3 patients were summarized, and the patients’ profiles, symptoms, sites and locations in the joint involved by FTS, magnetic resonance imaging (MRI) findings, surgical procedures, clinical courses, and cytogenetic analyses were reviewed.

Results

The average age of 26 cases was 40.9 years (range 13–69 years), and about 60% of the patients were male. About 10% of the patients had a past history of trauma to the knee joint. Of the present 3 cases, one case was extra-articular around the elbow joint, one case was extra-articular around the knee joint, and one case was intra-articular involving the knee joint. The common symptoms were pain (62.5%), swelling or palpable mass (54.2%), and limited range of motion of the involved joint (50%). The most commonly involved joint was the knee, with 32 cases (74.4%), followed by the elbow in 5 cases (11.6%), ankle in 4 (9.3%), and shoulder in 2 (4.7%). The tumor typically exhibited iso to low signal intensity on T1-weighted MRI. T2-weighted images showed various patterns, but mostly low signal intensity relative to muscle. The surgical margin was marginal resection in all cases. There were no recurrences after surgery. On chromosomal analysis, only the present Case 3 showed an abnormality.

Conclusions

A total of 43 FTS cases that occurred around large joints were summarized. The most common site was around the knee joint. In FTS cases around large joints, it is necessary to distinguish between various fibroblastic and/or fibrohistiocytic tumors.

Fibroma of tendon sheath on the medial side of the knee: a case report

Fibroma of tendon sheath, which is a benign soft tissue tumor, primarily affects the finger, hand, or wrist. It rarely involves the knee and only a few cases appear in the literature. Here, we report a case of fibroma of tendon sheath on the medial side of the knee, in a previously hardly reported location, and provide detailed imaging and histological findings. A 54-year-old man presented with his right knee pain and a palpable mass that had developed 3 months earlier. Magnetic resonance imaging showed isointensity in the soft tissue tumor on T1-weighted images, variable intensity on T2-weighted images, and contrast enhancement. The specimen obtained by needle biopsy showed no histological findings of malignancy. Marginal resection was performed and the microscopic diagnosis was fibroma of tendon sheath. Since fibroma of tendon sheath is relatively rare, the radiological feature is not specific, and a rate of local recurrence following excision is high, careful diagnosis, surgical treatment and long-term follow-up are necessary. J. Med. Invest. 64: 173-176, February, 2017.

Intra-articular fibroma of tendon sheath in a knee joint associated with iliotibial band friction syndrome

Iliotibial band (ITB) friction syndrome is a common overuse injury typically seen in the active athlete population. A nodular lesion on the inner side of the ITB as an etiology or an accompanying lesion from friction syndrome has been rarely reported. A 45-year-old male presented with recurrent pain and a movable nodule at the lateral joint area, diagnosed as ITB friction syndrome. The nodule was confirmed as a rare intra-articular fibroma of the tendon sheath (FTS) on the basis of histopathologic findings. We describe the MRI findings, arthroscopic and pathologic features, in this case of intra-articular FTS presenting with ITB friction syndrome.

Fibroma of the tendon sheath of the long head of the biceps tendon

Fibroma of the tendon sheath is a benign tumor that is less common than giant cell tumor of the tendon sheath. Both tumors may present as a painless, slowly enlarging mass. Radiological findings may be similar for both tumors. Histologically, fibroma of the tendon sheath lacks the hemosiderin-laden macrophages that are typical for giant cell tumor of the tendon sheath. We report on a 49-year-old woman with fibroma of the tendon sheath of the long head of the biceps tendon. In our case, on MR images, we observed band-like hypointense areas centrally in the tumor, mild patchy contrast enhancement, and most importantly, no decrease of signal intensity on gradient echo images. These characteristics reflected histological findings.