MR imaging of fibroma of the tendon sheath

Patellar Tendon Fibroma Mimicking Hemangioma: A Report on a Rare Case

Fibroma of the tendon sheath (FTS) is an uncommon benign soft tissue tumor of the tendon sheath. Clinical and radiological features are not distinctive enough to clinch the diagnosis preoperatively. FTS occurs mostly around small joints such as the fingers, hands, and wrist. However, it rarely arises around a large joint (knee, shoulder, elbow, or ankle). This case report describes a rare presentation of fibroma within the patellar tendon. The patient, a 35-year-old male, presented with progressive pain and swelling in his left knee. Clinical examination, imaging studies, and histopathological analysis mimicked hemangioma but confirmed the diagnosis of a patellar tendon fibroma. A surgical excision was performed, leading to significant improvement in symptoms and functional recovery. This case highlights the importance of considering rare soft tissue pathologies in the differential diagnosis of knee joint disorders.

Fibroblastic and Myofibroblastic Soft-Tissue Tumors: Imaging Spectrum and Radiologic-Pathologic Correlation

Fibroblastic and myofibroblastic tumors are a variable group of neoplasms ranging from benign to malignant. These lesions may affect patients of any age group but are more frequently encountered in the pediatric population. Patient clinical presentation depends on the location, growth pattern, adjacent soft-tissue involvement, and pathologic behavior of these neoplasms. In the 2020 update to the World Health Organization (WHO) classification system, these tumors are classified on the basis of their distinct biologic behavior, histomorphologic characteristics, and molecular profiles into four tumor categories: (a) benign (eg, fibrous hamartoma of infancy, nodular fasciitis, proliferative fasciitis, fibroma of the tendon sheath, calcifying aponeurotic fibroma); (b) intermediate, locally aggressive (eg, desmoid fibromatosis); (c) intermediate, rarely metastasizing (eg, dermatofibrosarcoma protuberans, myxoinflammatory fibroblastic sarcoma, low-grade myofibroblastic sarcoma, infantile fibrosarcoma); and (d) malignant (eg, sclerosing epithelioid fibrosarcomas; low-grade fibromyxoid sarcoma; myxofibrosarcoma; fibrosarcoma, not otherwise specified). Detection of various components of solid tumors at imaging can help in prediction of the presence of corresponding histopathologic variations, thus influencing diagnosis, prognosis, and treatment planning. For example, lesions with a greater myxoid matrix or necrotic components tend to show higher signal intensity on T2-weighted MR images, whereas lesions with hypercellularity and dense internal collagen content display low signal intensity. In addition, understanding the radiologic-pathologic correlation of soft-tissue tumors can help to increase the accuracy of percutaneous biopsy and allow unnecessary interventions to be avoided. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Multimodality imaging features of USP6-associated neoplasms

Since the discovery of USP6 gene rearrangements in aneurysmal bone cysts nearly 20 years ago, we have come to recognize that there is a family of USP6-driven mesenchymal neoplasms with overlapping clinical, morphologic, and imaging features. This family of neoplasms now includes myositis ossificans, aneurysmal bone cyst, nodular fasciitis, fibroma of tendon sheath, fibro-osseous pseudotumor of digits, and their associated variants. While generally benign and in many cases self-limiting, these lesions may undergo rapid growth, and be confused with malignant bone and soft tissue lesions, both clinically and on imaging. The purpose of this article is to review the imaging characteristics of the spectrum of USP6-driven neoplasms, highlight key features that allow distinction from malignant bone or soft tissue lesions, and discuss the role of imaging and molecular analysis in diagnosis.

Ultrasonography of fibroma of the tendon sheath in the hand and wrist

BACKGROUND

The purpose of our study was to explore the sonographic characteristics of fibromas of the tendon sheath of the hand and wrist and to evaluate the value of high frequency ultrasound in the diagnosis of FTS.

METHODS

We retrospectively reviewed the sonography of 42 patients with surgically proven FTS, including one with a relapsing tumor (43 lesions in total). The location, size, distribution, relationship with the surrounding tissue, two-dimensional gray-scale sonographic appearance and internal color blood flow of all lesions were analysed.

RESULTS

The maximum diameter ranged from 0.4 to 2.8 cm, with an average of 1.5 ± 0.6 cm. Twenty-eight lesions (65%) were associated with an adjacent tendon, while the other 15 lesions (35%) were next to the joint. Spindle or oval lesions were common, followed by irregular shape. The nodules with clear boundaries were hypoechoic and had posterior echo enhancement. Thirty-seven lesions (86%) were homogeneous, while 6 lesions (14%) had cystic components with no echo inside. Seventeen lesions (40%) had a large amount of blood flow. Nine lesions (20%) had a small amount of blood flow. The other 17 lesions (40%) had no significant blood flow.

CONCLUSIONS

The diagnosis of fibroma of the tendon sheath can be considered when ultrasound examination reveals a focal nodular mass adjacent to a tendon sheath with homogeneous hypoechogenicity and no or small or large amounts of blood flow.

Tendons and Tendon Sheaths of the Hand - An Update on MRI

BACKGROUND

 The tendons of the hand run in close proximity to each other and within retinacular tunnels adjacent to articular joints, while forming intersections in characteristic locations. The enclosing tendon sheaths are often sites of systemic or infectious inflammation.

METHOD

 This review article outlines the different entities of tendon and tendon sheath pathology and their manifestation in the hands. Diagnostic findings in tendon and tendon sheath disorders are illustrated using MRI imaging and discussed in context with the current literature.

RESULTS AND CONCLUSION

 Overuse may cause stenosis in the fibrous outer layer of the retinacula and the A1 annular ligaments as well as tendinosis. In contrast, proliferative tenosynovitis is a disease of the synovial inner layer of the tendon sheath with tendon infiltration and tendinitis. Pyogenic tenosynovitis favors the flexor compartments. Because of the narrow spaces in the hand, a high-resolution MRI technique must be used.

KEY POINTS

  · Diseases of the tendons and tendon sheaths may have a mechanical, degenerative, metabolic, systemic inflammatory, or infectious etiology.. · Fibrous tunnels and bony prominences in close proximity to crossing tendons predispose to mechanical tendon irritation at typical sites of the hand.. · Stenosing tenovaginitis occurs in the fibrous layer of the extensor retinaculum or the A1 annular pulleys. The most frequent manifestations are the "trigger finger" and de Quervain disease.. · Proliferative tenosynovitis affects the synovial layer of the tendon sheaths before infiltrating the tendons. The classic representative is rheumatoid arthritis..

CITATION FORMAT

· Schmitt R, Hesse N, Grunz JP. Tendons and Tendon Sheaths of the Hand - An Update on MRI. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1826-1007.

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.

An Update on Clinicopathological, Imaging and Genetic Features of Desmoplastic Fibroblastoma (Collagenous Fibroma)

Desmoplastic fibroblastoma (also known as collagenous fibroma) is an uncommon benign fibroblastic/myofibroblastic neoplasm that primarily arises in the subcutaneous tissue of upper extremity. Magnetic resonance imaging reveals a well-defined mass in intimate association with dense connective tissue and prominent low signal intensity on all pulse sequences. Peripheral and septal enhancement is usually seen after intravenous contrast. Histologically, the lesion is paucicellular and consists of spindle to stellate-shaped cells embedded in a collagenous or myxocollagenous stroma with low vascularity. Diffuse and strong nuclear immunoreactivity for FOS-like antigen 1 seems to be characteristic of desmoplastic fibroblastoma. Cytogenetic studies have demonstrated the presence of 11q12 rearrangements and an identical t(2;11)(q31;q12) translocation. This review provides an updated overview of the clinical, radiological, histological, cytogenetic and molecular genetic features of desmoplastic fibroblastoma and discusses the relationship to fibroma of tendon sheath.

Ultrasound and Magnetic Resonance Imaging Features of Calcifying Aponeurotic Fibromas

OBJECTIVES

To report characteristic imaging findings of calcifying aponeurotic fibromas (CAFs) on ultrasound (US) and magnetic resonance imaging (MRI).

METHODS

Eight patients with CAF based on our institutional pathology database from 2000 to 2019 were consecutively included. Images were assessed as follows: with plain radiographs for the presence of soft tissue calcifications; with US for the presence of microlithiasis (a nonshadowing hyperechoic focus <3 mm) and discrete calcifications, size, location, margin, echogenicity, and relationship with surrounding structures; and with MRI for the presence of MRI microlithiasis (scattered tiny signal-void dots), margin, signal intensity, contrast enhancement pattern, and relationship with surrounding structures.

RESULTS

Calcifying aponeurotic fibromas occurred most commonly in the foot (n = 5), followed by the hand, ankle, and knee, respectively. Half of the lesions (n = 4) showed intralesional calcifications on plain radiographs. On US, all lesions showed microlithiasis. They involved the subcutaneous (n = 5), perifascial (n = 2), and intermuscular (n = 1) layers. Margins were circumscribed (n = 3) or irregular (n = 5), whereas the echogenicity of the underlying tumor matrix was hyperechoic (n = 4), isoechoic (n = 2), or hypoechoic (n = 2). All lesions were abutting (n = 7) or encasing (n = 1) an adjacent tendon. On MRI, all CAFs showed tiny signal-void dots and irregular margins. Signal intensity was mostly hyperintense (n = 5) on T2-weighted images and all hypointense on T1-weighted images. Three lesions showed heterogeneous contrast enhancement, and 3 showed uneven marginal enhancement.

CONCLUSIONS

A CAF should be considered a differential diagnosis if a soft tissue mass abutting or encasing the tendon or fascia shows US or MRI microlithiasis.

Desmoplastic Fibroblastoma: An Uncommon Tumor With a Relatively Characteristic MRI Appearance

OBJECTIVE. We undertook this study to determine the radiologic features of desmo-plastic fibroblastoma. MATERIALS AND METHODS. We reviewed available radiologic images for 29 pathologically confirmed desmoplastic fibroblastomas, including images from MRI, radiography, ultrasound (US), and CT. RESULTS. The patient population included 14 women and 15 men (mean age, 60 years; range, 23-96 years). Typically, lesions were oval or lobulated and relatively small (mean, 5.6 cm). In 14 of the 22 cases that included patient histories, lesions had grown slowly, with two eventually causing pain. The remaining eight were discovered incidentally. All lesions involved or were below the deep fascia. Lesions were well-defined and associated with muscle (45%), deep fascia (28%), joint (21%), or tendon (7%). MR images were available in 26 cases; 14 included unenhanced and contrast-enhanced studies. On MRI imaging all lesions were well-defined and adjacent to dense connective tissue. On T1-weighted images, lesions showed varying amounts of low and intermediate signal intensity similar to that of tendon and skeletal muscle, respectively. On fluid-sensitive images, lesions were more heterogeneous, generally showing a wider spectrum of decreased to intermediate signal intensity. On contrast-enhanced MR images, enhancement was characteristically peripheral and septal with patchy areas of homogeneity. In the 10 cases with radiographs, images showed negative findings or a nonmineralized mass. The 10 available ultrasound studies showed mixed echogenicity. In eight patients, unenhanced CT showed lesions having attenuation similar to that of skeletal muscle. CONCLUSION. Desmoplastic fibroblastoma is an uncommon neoplasm with a relatively characteristic MRI appearance.

Fibroma of the tendon sheath of the neck

INTRODUCTION

Fibroma of the tendon sheath (FTS) is a rare benign tumour typically occurring in the extremities, but very rarely involving in the neck.

CASE REPORT

A 22-year-old male presented with a large painless mass of the right oropharynx. Magnetic resonance imaging (MRI) showed a well-circumscribed 7cm lesion in the right prestyloid space. The lesion was completely removed surgically. Histopathological examination revealed a fibroma of the tendon sheath of the stylohyoid muscle.

DISCUSSION

These tumours generally arise in the extremities of adults. To our knowledge, this is the first reported case of FTS in the neck.

Soft-Tissue Tumors of the Hand-Imaging Features

Imaging studies of the hands and fingers are common, and radiologists are generally comfortable with traumatic and degenerative conditions which arise frequently in daily practice. However, a variety of common and uncommon soft-tissue tumors also occur in the hand, the appropriate diagnosis of which can be a source of confusion for both clinicians and radiologists. These lesions often have overlapping imaging characteristics; however, a structured approach can help provide a focused differential diagnosis and impact further workup and management. We discuss several such tumors, categorizing them as cystic-appearing, noncystic masses along tendons and aponeuroses, adipocytic tumors, vascular lesions, and miscellaneous lesions with imaging features that can aid diagnosis.

A Case of 14-Year-Old Male with Fibroma of Tendon Sheath of the Hand with Novel Chromosomal Translocation 4;10

Fibroma of tendon sheath (FTS) is an uncommonly encountered soft tissue mass, which is morphologically distinct from the more commonly seen giant cell tumor of tendon sheath (GCTTS). Initially described in 1936, FTS is typically a slow growing, painless, firm mass with a predilection for the upper extremity, frequently involving the hand. Cases of associated triggering or compression neuropathies have been described when underlying tendons or nerves are affected. Currently, the literature on FTS is sparse and largely limited to case reports. More recently, few reports of cytogenetic analysis on FTS have been reported in the literature. Cellular and chromosomal analysis of FTS tissue revealed chromosomal translocations with yet unknown clinical significance. Here, we present a case report of FTS in a 14-year-old male with a painless enlarging mass on the palmar side of the left hand treated by excision. Subsequent karyotypic analysis revealed a chromosomal translocation t(4;10) (p16;q24), add (10)(q22)[24]. To our knowledge, this is the first description of this chromosomal aberration in the literature.

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.

Superficial radial nerve compression due to fibroma of the brachioradialis tendon sheath: A case report

Fibroma of the tendon sheath (FTS) is a rare benign tumour that usually develops in the upper extremity, particularly in the fingers, hands and wrists. Herein, we present the case of a patient with an unusually localised FTS compressing the superficial branch of the radial nerve. A 62-year-old woman presented with a superficial radial nerve compression due to FTS of the brachioradialis. Histopathological diagnosis was confirmed as a FTS after marginal excision. The patient who had compression-related symptoms in the superficial branch of the radial nerve recovered completely at one month after surgery. One year later, the patient remained free of symptoms and no recurrence was observed.

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.

Fibroma of tendon sheath embedded in carpal bones mimicking carpal enchondroma: A case report

RATIONALE

Fibroma of tendon sheath is a rare entity that is typically attached to the tendon sheath.

PATIENT CONCERNS

A 43-year-old man presented with a painful mass in his right wrist, which was initially misdiagnosed as an enchondroma.

DIAGNOSIS

Fibroma embedded into carpal bones, which exhibited lytic radiographic features similar to those of enchondroma. Excisional biopsy demonstrated spindle-shaped cells and collagen-like stroma.

INTERVENTIONS

The patient underwent lesion resection surgery.

OUTCOMES

The patient recovered well and showed no signs of recurrence at 6-month follow-up.

LESSONS

This case provides valuable insights for hand surgeons. While radiograph is helpful in multiple diseases, histological examination is indispensable for establishment of final diagnosis.

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 Presenting Limited Flexion of the Fingers

A 35-year-old Japanese man presented with a 1-month history of limited flexion and radiating pain in the left middle and ring fingers. A physical examination revealed a hard nodular mass in his left palm. Magnetic resonance imaging showed a 2 × 1.5 × 1 cm mass of low intensity on T1-weighted images and high intensity on T2-weighted images and gadolinium enhancement. The tumor was marginally resected, adhering to the flexor digitorum profundus of both the third and fourth fingers. The histological diagnosis was fibroma of tendon sheath. After the surgery, the range of motion and hand function were improved. No recurrence has been observed. Fibroma of tendon sheath usually arises on the fingers and hands with strong attachment to the tendon or tendon sheath. The tumor in the present case probably limited the range of flexion of the fingers by obstruction of the transverse carpal ligament.

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.

Fibroma of tendon sheath in planta

PURPOSE

Fibroma of tendon sheath in planta is comparatively rare, and its differentiate diagnose, tumour features, treatment and complications were lack of retrospective study in clinics.

METHODS

This was a retrospective study of 13 patients (seven women, six men) operated between July 2001 and May 2013 for FTS in planta. The average age at the time of the procedure was 49.8 ± 8.3 years old (range 31-64). The female-to-male ratio was 9:4. Before the surgery, anteroposterior, lateral and oblique position of foot X-rays were performed in all patients. Ultrasonography (n = 11) and magnetic resonance imaging (n = 11) were performed selectively. The tumor located on the metatarsal par (n = 6), the central part of plantar (n = 4), the lateral part (n = 2) and the medial part (n = 1). Eight patients presented with painless mass (62 % of cases), while five patients presented with pain mass (38 % of cases). No patient had bony erosion. This paper studies the different features of FTS and classifies them into two types-superficial type that tumour grows at planter fascia; deep type that breaks through the planter fascia growing around tendon and joint capsule. Eight and five patients were diagnosed as superficial type and deep type respectively.

RESULTS

In all cases, the tumor was excised, pathological results was FTS. The mean follow-up period was 3.2 ± 1.1 years (range 2-7) years. Five patients had neurovascular bundle involvement (38 % of cases). Two patients had a recurrence (15 % of cases), they undergone another operation. Four patients had a pain (31 % of cases), two patients had numbness (15 % of cases), and one patient had pain and numbness (8 % of cases). They recovered after conservative treatment.

CONCLUSION

For the FTS that grows in the plantar, we should select differential diagnosis and the corresponding therapy according to the features of two types, also the prognosis is different.

LEVEL OF EVIDENCE

IV.

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.

Focal hand lesions: review and radiological approach

Focal hand lesions are commonly encountered in clinical practice and are often benign. Magnetic resonance (MR) imaging is the imaging modality of choice in evaluating these lesions as it can accurately determine the nature of the lesion, enhancement pattern and exact location in relation to surrounding tissues. However, while MR features of various soft tissue lesions in the hand have been well described, it is often still difficult to differentiate between benign and malignant lesions. We review the MR imaging features of a variety of focal hand lesions presenting at our institution and propose a classification into "benign", "intermediate grade" (histologically benign but locally aggressive with potential for recurrence) and frankly "malignant" lesions based on MR findings. This aims to narrow down differential diagnoses and helps in further management of the lesion, preoperative planning and, in cases of primary malignancy, local staging. Teaching Points • Hand lesions are often benign and MR is essential as part of the workup. • MR features of various hand lesions are well described but are often non-specific. • Certain MR features may help for the diagnosis but histological examination is usually required. • We aim to classify hand lesions based on MR features such as margin, enhancement and bony involvement. • Classifying these lesions can help narrow down differential diagnoses and aid management.

Intra-articular fibroma of tendon sheath arising in the acromioclavicular joint

Fibroma of the tendon sheath, a rare benign soft tissue tumor that most often occurs in the distal upper extremities (hands and wrist), is exceedingly rare to present as an intraarticular mass. Presented here is the first case in the English literature, to our knowledge, of a fibroma of the tendon sheath arising in the acromioclavicular joint. The patient presented with recurrent shoulder pain with activity without antecedent trauma. Radiographs were essentially normal. MR images demonstrated a lobulated, heterogeneous mass with contrast enhancement arising from the acromioclavicular joint. Following surgical resection, histopathology revealed hypocellular collagen matrix with spindle-shaped fibroblasts, confirming the diagnosis of fibroma of tendon sheath. The imaging features of the fibroma of the tendon sheath and a brief review of the literature are presented.

Fibroma of tendon sheath located within Kager's triangle

The formation of a fibroma of the tendon sheath, a rare, slow-growing, benign tumor, usually occurs in the upper extremities of young adult males. We present an extremely rare case of a fibroma of the tendon sheath arising adjacent to the Achilles tendon within Kager's triangle in a 41-year-old female. The patient presented with progressive pain localized to the posterior aspect of the left ankle. Complete excision and histopathologic analysis of the fibroma were performed. The patient experienced an uneventful recovery after the intervention and had no evidence of recurrence after 3 months of follow-up. Fibroma of the tendon sheath should be included in the differential diagnosis when a patient presents with a painful soft tissue mass in Kager's triangle.

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.

Tendon sheath fibroma in the thigh

Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patient's lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patient's tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men.

Indeterminate soft-tissue tumors of the hand and wrist: a review based on a clinical series of 39 cases

Soft-tissue masses located at the hand and wrist are a frequent clinical presentation. The majority of these are ganglia, which have characteristic imaging features. Other common masses in which a diagnosis is suggested by imaging include hemangiomas, lipomas, and focal synovitis. The remainder are rare although a diagnosis may be attempted by considering the patients' age and the location. We reviewed 39 soft-tissue masses at the hand and wrist referred to our institution between September 1998 and January 2006 that had indeterminate imaging features. The majority were benign neoplastic lesions with the most common being a giant cell tumor of the tendon sheath, followed by angioleiomyoma, peripheral nerve sheath tumor, fibromatosis, fibroma of tendon sheath, and solitary fibrous tumor. These lesions tend to occur in young adults at the metacarpal level. However, there are no imaging features that can reliably differentiate between benign and malignant tumors.

Tumors and diseases of the joint

A variety of different diseases affect the synovium, including infection, noninfectious immunologic inflammatory conditions, degenerative arthroses, crystal deposits, trauma, and tumors. Tumors of the synovium are relatively uncommon. Any mesenchymal tumor may arise in the synovium, but most recapitulate its normal counterpart including synoviocytes, blood vessels, fat, and fibrous tissue. These tumors can arise in any synovial lined structures both within joints and in extraarticular locations. Most synovial tumors are benign. Malignant tumors are rare but important to recognize because many are aggressive and must be treated appropriately. Among common nonneoplastic conditions that affect the synovium and surrounding structures are crystal deposits such as monosodium urate crystals, calcium pyrophosphate dihydrate crystals, and hydroxyapatite crystals. These crystal deposits may be asymptomatic or cause severe pain or chronic joint destruction. Their accurate identification is important to guide appropriate therapy.

Intraarticular fibroma of tendon sheath

A 17-year-old male presented to us following a hyperflexion injury to his right knee sustained while playing soccer. Immediately after the traumatic event, he developed a large, tense knee effusion. Physical examination revealed limited range of motion. MRI revealed a lobulated mass in the posteromedial aspect of the knee joint. The mass was excised and sections submitted to pathology. A pathologic, microscopic, and immunohistochemical characteristics revealed the final diagnosis of fibroma of tendon sheath in the knee. At 12 months followup, the patient reported no subjective symptoms, such as pain or limitation of athletic activities and has full range of motion. Additionally, he has demonstrated no signs of recurrence. We report a case of fibroma of the tendon sheath originating from the synovial membrane of the joint capsule of the knee.

Cyst-like solid tumors of the musculoskeletal system: an analysis of ultrasound findings

OBJECTIVE

When evaluating superficial soft tissue masses with ultrasonography, it is not always clear whether the mass is cystic or solid. We reviewed sonograms of soft tissue masses, which were interpreted as cystic but confirmed as solid tumors.

MATERIALS AND METHODS

We scanned a database of patients with superficial soft tissue masses from two different institutions. Four hundred and thirty lesions were evaluated with ultrasonography and then confirmed surgically. Twenty-three masses were identified, of which initial interpretation on gray scale included cystic tumor which pathology revealed to be solid tumors. All images were evaluated by two musculoskeletal radiologists, regarding internal echogenicity of lesions, presence of posterior enhancement, margins, size, and internal vascularity.

RESULTS

Of 23 masses, there were 5 giant cell tumors of the tendon sheath, 4 schwannomas, 3 vascular leiomyomas, 2 benign fibrous histiocytomas, 2 dermatofibrosarcoma protuberans, 2 granular cell tumors, 1 dermatofibroma, 1 fibroma of the tendon sheath, 1 fibromatosis, 1 eccrine spiradenoma, and 1 granulation tissue. Masses were hypoechoic in 16 and anechoic in 7 cases. Posterior enhancement was present in 9, and 10 masses showed no internal vascularity on color Doppler imaging. Margins were smooth in 13, smooth with mild lobulation in 7, and lobulated in 3 cases. Mean size was 2.3 cm.

CONCLUSION

On ultrasonography, solid soft tissue tumors may be confused with cystic masses. Such cases are not common, and fibrous tumors are the most frequent. Care should be given to these solid tumors that have a cystic appearance and even lack internal vascularity on color Doppler imaging to enhance diagnosis of cystic and solid masses.

Magnetic resonance imaging in the visualization of benign tumors and tumor-like lesions of hand and wrist

The differential diagnosis of benign tumors and tumor-like lesions of the hand and wrist region is important with regard to choosing the therapy (medical versus surgical), or to decide to just follow-up the lesion. In most of the cases the proper analysis of MRI findings in correlation with the patient's history is sufficient to meet a specific diagnosis. However, diagnostic confusion is not uncommon as there are numerous lesions affecting the hand and wrist region. This pictorial essay offers a practical radiological approach to benign tumors and tumor-like lesions of the hand and wrist region based on most frequently observed MRI findings.

Fibroma of tendon sheath located within the ankle joint capsule

We report a very rare case of fibroma of the tendon sheath arising from the anteromedial ankle joint capsule, with no apparent connection to any tendon in the area, found in a 58-year-old patient complaining of progressive local swelling. This uncommon tumor has its usual localization in tendon sheaths, is extremely rare in joint capsules, and has never been described in this location previously. MRI showed nonuniform low signal intensity in T1- and T2-weighted images and high intensity in STIR images. The mass was completely excised by open surgery. Histopathological analysis later confirmed the diagnosis of a fibroma of the tendon sheath.

Pediatric soft-tissue tumors and pseudotumors: MR imaging features with pathologic correlation: part 2. Tumors of fibroblastic/myofibroblastic, so-called fibrohistiocytic, muscular, lymphomatous, neurogenic, hair matrix, and uncertain origin

In the final part of this two-part review article on soft-tissue masses in children, the magnetic resonance (MR) imaging features, clinical findings, and pathologic findings in a wide variety of tumors, including those of fibroblastic/myofibroblastic origin, so-called fibrohistiocytic tumors, smooth-muscle tumors, skeletal-muscle tumors, tumors of uncertain differentiation, and lymphoma, are described. Other neoplasms that are not included in the World Health Organization classification of soft-tissue tumors but may be seen clinically as soft-tissue masses, specifically dermatofibrosarcoma protuberans, neurogenic tumors and pilomatricoma, are also included. In contrast to the tumors reviewed in Part 1 of this review, the MR imaging features and clinical findings of the tumors included here are largely nonspecific. However, MR imaging is useful in determining site of tumor origin, extent of disease, and relation of tumor to adjacent anatomic structures, and for follow-up after therapy. In some of these entities, the combination of findings may aid in narrowing the differential diagnosis, such as persistent low signal intensity on T1- and T2-weighted images in some fibroblastic lesions, identification of hemosiderin and a synovial origin in pigmented villonodular synovitis, or the presence of multiple target signs on T2-weighted images in deep plexiform neurofibroma. In a large number of cases, however, tissue biopsy is required for final diagnosis.

Intraarticular fibroma of the tendon sheath arising from the infrapatellar fat pad in the knee joint

We report a rare case of fibroma of the tendon sheath arising from the fat pad in the knee. To our knowledge, only four previous cases of fibroma of the tendon sheath in the knee have been reported in the English literature. In our case, magnetic resonance imaging showed low signal intensity in the mass on T1- and T2-weighted images. The mass was excised by mini arthrotomy.

Mineralized fibroma of the tendon sheath presenting as a bursitis

We report on the clinical, imaging-including ultrasound, computed tomography, and magnetic resonance imaging-and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient.

Tumour and tumour-like lesions of the intercondylar notch of the knee: a pictorial review

A variety of tumours and tumour-like lesions are found in the intercondylar notch of the knee. MR imaging is the technique of choice in evaluating these conditions. Correlation with radiographs is important to identify those lesions containing calcification. This review article discusses the imaging features of tumour and tumour-like lesions involving the intercondylar notch with an emphasis on MR imaging features that suggest a specific diagnosis.

Radiological Reasoning:Acutely Painful Swollen Finger

OBJECTIVE

The purpose of this article is to review the differential diagnosis of finger masses and their imaging appearances.

CONCLUSION

Giant cell tumor of the tendon sheath is a slowly growing, benign tumor of the synovium that commonly presents as a painless nodular mass in the hand or wrist. Also termed "localized nodular tenosynovitis," these tumors are the most common soft-tissue tumors of the hand. Occasionally, these tumors can present with pain when traumatized, and they should be suspected when a firm, rubbery mass is found at the location of a tendon sheath.