1: Skeletal Radiol. 2006 Apr;35(4):244-7. Epub 2005 Oct 19

Tenosynovial lipoma arborescens of the ankle in a child.

Huang GS, Lee HS, Hsu YC, Kao HW, Lee HH, Chen CY.

Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, 325, Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan, Republic of China, gsh5@seed.net.tw.

Lipoma arborescens is a rare entity of the synovium and frequently occurs in the joints. Lipoma arborescens involving the synovial sheaths of the tendons is exceedingly rare. We report a case of a 12-year-old girl with lipoma arborescence affecting the synovial sheaths of the peroneal, posterior tibialis, and flexor tendons. Identification of the typical features of fat tissues in the proliferative synovium on MRI may help in making a correct diagnosis. The clinical presentation and MRI findings are described, and the entity is briefly reviewed.

2: Knee. 2005 Oct;12(5):394-6.

Lipoma arborescens of the knee.

Davies AP, Blewitt N.

Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK. andydavies@hotmail.com

Lipoma arborescens (diffuse articular lipomatosis) is a rare, benign intra-articular lesion of unknown aetiology. It is characterised by villous proliferation of the synovium and diffuse replacement of the subsynovial tissue by mature fat cells. It forms part of the differential diagnosis for a slowly progressive chronically swollen knee. We present a very rare case of bilateral involvement of the knee and discuss the symptoms, diagnosis and treatment of this condition.

3: Skeletal Radiol. 2005 Sep;34(9):536-8. Epub 2005 Mar 22

Lipoma arborescens affecting multiple joints.

Bejia I, Younes M, Moussa A, Said M, Touzi M, Bergaoui N.

Department of Rheumatology, EPS Monastir, Monastir, Tunisia. ismail.bejia@lycos.com

Lipoma arborescens is a rare benign intra-articular lesion of unknown etiology that usually involves the suprapatellar pouch of the knee joint. Clinically, the most common finding is a slow-growing painless swelling, accompanied by intermittent effusion of the joint. We report a case of a multifocal lipoma arborescens localized in the knees and the hips in a 24-year-old man, initially mimicking an inflammatory arthropathy. The diagnosis of lipoma arborescens was made by magnetic resonance imaging of the hips and the knees. Under arthroscopic guidance, the synovial biopsy of the right knee disclosed the specific histological signs of lipoma arborescens. As far as we know, this is the third case of multifocal lipoma arborescens reported in the English literature.

4: Arthroscopy. 2005 Jan;21(1):98-102.

Intra-articular lipoma of the knee joint in a girl.

Yilmaz E, Karakurt L, Akpolat N, Ozdemir H, Belhan O, Incesu M.

Department of Orthopaedics and Traumatology, Firat University, Medical Faculty, Elazig, Turkey. yilmazerh@yahoo.com

Intra-articular lipoma is a rare benign mass that commonly occurs in the knee joint. We present the case of a 15-year-old girl with a slowly growing mass in her right knee. There was no history of trauma. The patient had no catching, locking, or giving way of the knee. On magnetic resonance imaging, multiple fibrous septa within a hyperintense mass was determined. After the arthroscopic examination, complete resection by open surgery was performed. There was no tumor recurrence at the end of the 1-year follow-up period. True intra-articular lipoma should be distinguished from lipoma arborescens, which is a similar but more common condition.

5: Arthroscopy. 2004 Oct;20(8):e95-9.

Lipoma arborescens of the knee.

Kim RS, Song JS, Park SW, Kim L, Park SR, Jung JH, Park W.

Department of Orthopaedic Surgery, INHA University Hospital, INHA University College of Medicine, Jung-gu, Incheon, Korea. keelim@inha.ac.kr

Lipoma arborescens are rare lesions, typically located in the knee. They have a predilection for the suprapatellar pouch in the knee joint, but can also occur in any area of the knee joint. Magnetic resonance imaging of lipoma arborescens often reveals subchondral bone cyst and/or bone erosions, and there may appear to be a correlation between lipoma arborescens and osteoarthritis. We describe a case of histologically proven lipoma arborescens in the suprapatellar pouch and infrapatellar area of the knee with no damage to the posterior compartment and bone erosion in the proximal tibia without osteoarthritis.

6: Acta Med Port. 2004 Jul-Aug;17(4):325-8. Epub 2004 Aug 31.

[Synovial lipoma arborescens]

[Article in Portuguese]
Bernardo A, Bernardes M, Brito I, Vieira A, Ventura F.

Servicos de Reumatologia e de Radiologia Hospital de S. Joao, Porto.

Lipoma arborescens is a rare intraarticular lesion of unknown etiology. The disorder usually presents as painless swelling and recurrent joint effusion. It is typically located in the knee (especially the suprapatellar bursa), though it has also been described in other joints. Laboratory test results are normal, as well as aspirated synovial fluid. Synovectomy is curative in most cases. The authors report a review of the literature, highlighting the importance of magnetic resonance imaging in the diagnosis of this pathology. Although it is a rare lesion, synovial lipoma arborescens should be included in the differential diagnosis of patients with a chronic swollen joint or recurrent joint effusions.