An unusual case of lipoma arborescens

Synovial Lipomatosis With Extra-articular Extension in the Arthritic Wrist: An Unexpected Diagnosis

ABSTRACT

Synovial lipomatosis is a rare condition characterized by adipocyte proliferation within joint synovial tissue. It most commonly affects the knee and is typically intra-articular. Only 5 published case reports describe extra-articular synovial lipomatosis of the wrist. We present a case of a sexagenarian patient seen for his wrist arthropathy. His x-ray revealed pan-wrist arthritis and inflammatory soft tissue swelling. The patient was slated for a wrist fusion and Darrach procedure. Following the dorsal skin incision in the operating room, an unusual adipose mass was identified infiltrating all extensor compartments: midcarpal, radiocarpal, and distal radioulnar joints. The mass was excised and sent to pathology prior to proceeding with the slated surgery. Synovial lipomatosis was diagnosed postoperatively based on histopathology. Six weeks postoperatively, the wrist fusion had healed clinically and radiographically, and his pain had improved. There was no evidence of recurrence. Synovial lipomatosis is a rare entity that may imitate multiple other pathologies. It is possible that synovial lipomatosis may represent a secondary occurrence following degenerative articular disease or trauma in older patients. This is the first case report to date describing synovial lipomatosis of the wrist with extra-articular extension in the setting of pan-carpal wrist arthritis.

Adipocytes in synovial fluid cytology: An approach for diagnosing synovial lipomatosis

A 2-year-old neutered male bullmastiff dog was presented with chronic left hind limb lameness. Physical examination revealed left stifle effusion and medial buttress without cranial tibial thrust. Radiographs showed joint effusion and new bone formation at the patella apex. Magnetic resonance imaging showed increased synovial fluid, widening of the joint space, abnormal infrapatellar fat body and thinning of the cranial cruciate ligament. Synoviocentesis and cytologic evaluation of synovial fluid revealed marked mononuclear inflammation with abundant fatty tissue, suggesting synovial lipomatosis in conjunction with the imaging findings. The disease was confirmed histologically after sampling the lesion during arthrotomy. Synovial lipomatosis, characterized by extensive synovial adipose tissue proliferation of the synovial membrane, is a rare "tumor-like" disorder that usually affects the stifle. Although the etiology remains unclear, joint trauma, inflammation, instability, and lipid abnormalities have been proposed as causes. Inflammatory factors may promote synoviocyte and adipocyte hyperplasia that perpetuate the process. Surgical removal may be suggested to eliminate triggers and prevent future recurrences. The report provides the first cytological description of adipocytes in synovial fluid associated with the diagnosis of synovial lipomatosis in dogs. This case report underscores the potential effectiveness of cytologic analysis of synovial fluid smears, in combination with magnetic resonance imaging (MRI), for diagnosing this condition and reducing complications associated with arthrotomy for sampling purposes. Additionally, the case highlights that synovial lipomatosis should be considered as a potential differential diagnosis for synovial masses in dogs. Further cases are needed to validate these observations in veterinary medicine.

Case Report: Synchronous bilateral lipoma arborescens of the bicipitoradial bursa

Background: Lipoma arborescens (LA) is an infrequent benign tumor made of mature sub-synovial fatty cell proliferation that may arise into the synovial joint, the bursae or the tendon sheaths. This condition affects mainly the knee joint, but the bicipitoradial bursa is an exceptional location. We report herein a case of a synchronous bilateral (LA) of the bicipitoradial bursa. Case presentation: A 52-year-old patient, with no medical history, presented with a swelling of both front arms that had been progressing for nine years. Physical examination showed a mass in the antecubital fossae of 3cm on the left side and 0.5cm on the right side. Both masses were tender, well-defined, fixed, without inflammatory signs and painful on elbow flexion. A magnetic resonance imaging (MRI) scan was performed, revealing the presence of a septate soft-tissue mass of the distal portion of the brachial muscle of 70x46x27mm. This mass had a heterogeneous fat signal in its depth and a homogeneous fat composition on the outside. The diagnosis of liposarcoma was suspected. The patient underwent surgery to remove both masses. Gross examination showed a characteristic frond-like or digitiform pattern. Microscopical examination demonstrated papillary proliferation of the synovial villi. The final diagnosis was of LA. The patient had no complications and there was no recurrence of LA. Conclusions: LA is a rare condition, and the bicipitoradial bursa is an exceptional location. Histological confirmation is mandatory to correct the diagnosis.

Incidental Intraoperative Finding of Bilateral Lipoma Arborescens in a Patient Undergoing Bilateral Total Knee Replacement

Lipoma arborescens (villous lipomatous proliferation of the synovial membrane) is a rare, benign articular lesion characterized by diffuse villous proliferation of the synovium with mature fat substitution of the sub-synovial connective tissue. The etiology of this condition still remains unknown. It represents part of differential diagnosis for a progressive swollen knee with chronic pain secondary to synovial proliferative disorders with or without associations with osteoarthritis. We report an intraoperative finding of lipoma arborescence in a patient who underwent bilateral primary total knee replacement secondary to advanced osteoarthritis.

Surgical management of upper limb lipoma arborescens: a systematic review

Background

Lipoma arborescens (LA) is a rare benign synovial tumour characterized by the proliferation of mature adipocytes within the synovial cells. Given its rarity, current evidence is mainly based on case reports and case series, and no guidelines are available. The present study investigated the current surgical management and related outcomes of LA in the upper limb.

Methods

This systematic review was conducted following the PRISMA guidelines. PubMed, Scopus, and Virtual Health Library were accessed in September 2021. Clinical studies evaluating patients with LA undergoing surgical treatment were considered eligible for this systematic review. Only studies which reported data on LA located in the upper limb with histopathological confirmation were considered. Articles that reported data from nonsurgical management were not considered.

Results

A total of 21 studies reporting 22 lesions in 21 patients were assessed. The mean age of the patients was 48.48 years (range 22–77). Most studies evaluated the restoration of range of motion and symptom resolution for the functional outcome assessment. Open or arthroscopic excision and synovectomy were the most common surgical procedures for LA. The concomitant lesions were treated in a single-stage procedure. All patients had satisfactory outcomes after open or arthroscopic excision and synovectomy without recurrence at a mean follow-up of 21.14 months (range 2–60). One patient developed postoperative cellulitis (4.55%).

Conclusion

Open and arthroscopic excision combined with synovectomy should be considered the standard treatment option of upper limb LA. Concomitant pathologies can be addressed in a one-stage procedure. Although LA was recognized as a clinical entity decades ago, there is a lack of evidence based guidelines and long term outcome data are unavailable.

Arthroscopic treatment of a lipoma arborescens of the elbow: A case report

INTRODUCTION

Lipoma Arborescens is a rare pathology that mainly affects the knee. Occurrences in the elbow are even more uncommon and mainly involve the bicipitoradial bursa.

CASE'S DESCRIPTION

We describe the case of a 54-year-old patient known for rheumatoid arthritis, who consulted for chronic elbow pain associated with swelling and limited extension.

DIAGNOSIS

The diagnosis of a lipoma arborescens of the elbow involving the whole joint was made using magnetic resonance imaging and confirmed during arthroscopy.

INTERVENTIONS

After a failed nonoperative treatment consisting in intra-articular cortisone injections and physiotherapy, the patient underwent arthroscopic synovectomy and arthrolysis.

OUTCOME

At 1-year follow-up, he reported no pain, satisfactory range of motion, and major improvements in clinical scores.

CONCLUSION

This is the first illustrated case report about lipoma arborescens involving the whole elbow joint. Even though it is a rare disease, awareness of its presentation, imaging patterns, and treatment options is therefore important for clinicians, radiologists, and surgeons. In this case, arthroscopic treatment resulted in satisfactory and long-lasting pain relief and functional results. It may be considered as a safe and effective option in case of failed nonoperative measures.

Progressive bilateral lipoma arborescens of the knee caused by uncontrolled juvenil idiopathic arthritis

Lipoma arborescens (LA) is a chronic, slowly progressive intra-articular lesion characterized by villous lipomatous proliferation of the synovium. Most cases have been described in elderly patients with degenerative or post-traumatic joint disease, but in several case reports, it has been considered to be related to inflammatory joint diseases. Here, we report a case of 17 years old female firstly presenting with bilateral swelling in both knees of five years duration, followed by the development of wide spread lipoma arborescens associated with the uncontrolled treatment of juvenile idiopathic arthritis.

Lipoma arborescens - Uncommon Diagnosis for Joint Swelling: Case Report and Review of the Literature

INTRODUCTION

Soft tissue swelling of the knee joint can be caused by many diseases. Lipomas are one of the most reasonable differential diagnoses we have to consider. Therefore, we now present the uncommon case of a Lipoma arborescens (LA) and differentiate it from a quite similar manifesting spindle cell lipoma as follows.

CASE REPORT

A 49-years old patient reports about progressive knee pain for four years and observes an increasing joint swelling. This swelling is a soft tissue, shiftable tumour, not painful. The magnetic resonance imaging (MRI) with contrast agent brings the diagnosis of an advanced osteoarthritis of the knee joint and classifies the tumour as LA. Subsequently, we treat the osteoarthritis by implanting a total knee arthroplasty with simultaneous intraoperative tumour resection performed as total synovectomy. The histopathological processing confirms the clinically and radiologically made diagnosis of LA.

SUMMARY

Lipoma arborescens presents an uncommon subgroup of Lipomas, which is characterized by a slowly progressive increasing soft tissue swelling, especially around bigger human joints. Due to its intraarticular location, the LA might become clinically relevant when it reaches a certain tumour size. Looking at the diagnostics, sonography, MRI and especially the histopathological processing give the crucial results. Final proof can only be made by histopathological examination. Additionally, we have some differential diagnoses to exclude. Under these we predominantly find the spindle cell lipoma, synovial haemagioma, vascular synovial malformations and tenosynovial giant-cell tumour. Furthermore, an atypical lipomatous tumour should be excluded by FISH-analysis via determining the MDM2-Genamplification.

Lipoma arborescens of the bicipitoradial bursa

Lipoma arborescens (LA) is a rare, benign articular lesion that is most commonly found within the suprapatellar recess of the knee. An extremely rare case of LA involving unilateral bicipitoradial bursa is described in this study. A 58-year-old male presented with a superficial soft mass on the volar aspect of the left forearm. The magnetic resonance imaging (MRI) examination demonstrated a lobulated complex mass containing multiple frond-like fatty nodules, along the distal biceps tendon in the bicipitoradial bursa. Ultrasound-guided biopsy of the lesion confirmed the diagnosis of LA and patient was scheduled for surgical excision. Recognizing the characteristic imaging of LA, particularly on MRI, is essential for accurate pre-procedural diagnosis.