Lipoma arborescens
•Download as PPTX, PDF•
3 likes•1,408 views
Lipoma arborescens is a rare benign condition where the synovial lining of joints is replaced by hypertrophied villi containing mature fat cells. It most commonly affects the suprapatellar bursa of the knee. Patients typically present with painless joint swelling and effusion. MRI is the best imaging method, demonstrating frond-like proliferations of high signal fat within effusions. Treatment involves synovectomy, with rare recurrence. It must be differentiated from other intra-articular masses and synovial proliferative disorders.
Recommended
More Related Content
What's hot
What's hot (20)
Similar to Lipoma arborescens
Similar to Lipoma arborescens (20)
More from Bangabandhu Sheikh Mujib Medical University (BSMMU)
More from Bangabandhu Sheikh Mujib Medical University (BSMMU) (9)
Recently uploaded
Recently uploaded (20)
Lipoma arborescens
- 1. LIPOMA ARBORESCENS DR. MAHESH CHAUDHARY PHASE-B RESIDENT RADIOLOGY & IMAGING, BSM MEDICAL UNIVERSITY
- 2. INTRODUCTION • Lipoma arborescens is a rare condition affecting synovial linings of the joints and bursae, with 'frond like' depositions of fatty tissue. • They account for less than 1% of all lipomatous lesions • Originally described by Hoffa, the macrospic frond like appearance was felt to resemble a tree in leaf; hence, the Latin term arborescens (meaning “tree- forming” or “treelike”)
- 3. EPIDEMIOLOGY • Patients typically present in the 5th-7th decades but the condition has also been reported in young • Usually these lesions are sporadic, however they can be seen in the setting of osteoarthritis, collagen vascular disorders or previous trauma
- 4. CLINICAL PRESENTATION • Painless joint swelling, frequently with an associated effusion. • The most frequent site of involvement is suprapatellar bursa of knee joint, and the disorder is usually unilateral • Occasional reports of hip, shoulder, wrist elbow are also reported. • Other joint involvement is uncommon. • Involvement of tendon sheath is even rarer.
- 5. PATHOLOGY • The normal synovium is replaced by hypertrophied villi demonstrating marked deposition of mature lipocytes within them
- 6. ASSOCIATIONS • joint effusion: very common • degenerative changes: common • meniscal tears: common • synovial cysts: uncommon • bone erosions: uncommon • chondromatosis: uncommon to rare • patellar subluxation: rare • discoid meniscus: rare
- 7. RADIOGRAPH • Occasionally plain films are able to detect fatty lucencies within a soft tissue lesion, although usually the large associated effusion dominates the film. • Coexistent degenerative changes are frequently present. • Bony erosions are uncommon
- 8. ULTRASOUND • Demonstrates a joint effusion with echogenic 'frond like' projections into the effusion.
- 9. CT • CT is able to demonstrate a low density intra-articular mass. • Aftter contrast: No or little if any enhancement is seen. • As joint fluid is volume-averaged with the lesion, it is of higher density than fat, but lower than water.
- 10. CT
- 11. MRI • MRI is the modality of choice for diagnosis. • T1: high signal • T2 & PD : less high signal • T2FS & STIR: low signal • Gradiant echo (GE): chemical shift artefact is sometimes seen at the fat-fluid interface • Typically, there is frond-like proliferation of fat-containing cells. Where effusions coexist, visualisation of the fronds is improved.
- 13. TREATMENT • The condition is benign and is cured by synovectomy. • Recurrence is uncommon
- 14. DIFFERENTIAL DIAGNOSIS • Loose bodies • often calcified • MRI hyopintense • Synovial osteochondromatosis/synovial chondromatosis • circumscribed loose bodies • erosions common • may calcify
- 16. DD • Pigmented villonodular synovitis (PVNS) • MRI demonstrates low signal on T2 weighted images • no fat signal • Synovial haemangioma • enhancement is more conspicuous • occasionally fluid-fluid levels are seen • Synovitis • thickened synovium but no fat signal
- 17. PVNS
- 18. REFERENCES • 1. Senocak E, Gurel K, Gurel S et-al. Lipoma arborescens of the suprapatellar bursa and extensor digitorum longus tendon sheath: report of 2 cases. J Ultrasound Med. 2007;26 (10): 1427-33. J Ultrasound Med (full text) - Pubmed citation • 2. Giant synovial lipoma arborescence of the right knee in a 76-year-old diabetic woman with purulent joint effusion. Çukur S, Belenli OK, Yücel I, Yazici B. Aegean Pathology Society, APJ, 3, 10–13, 2006. • 3. Meyers SP. MRI of bone and soft tissue tumors and tumorlike lesions, differential diagnosis and atlas. Thieme Publishing Group. (2008) ISBN:3131354216. Read it at Google Books - Find it at Amazon • 4. Manaster BJ, Disler DG, May DA et-al. Musculoskeletal imaging, the requisites. Mosby Inc. (2002) ISBN:0323011896. Read it at Google Books - Find it at Amazon • 5. Sheldon PJ, Forrester DM, Learch TJ. Imaging of intraarticular masses. Radiographics. 25 (1): 105-19. doi:10.1148/rg.251045050 - Pubmed citation • 6. Greenspan A, Jundt G, Remagen W. Differential diagnosis in orthopaedic oncology. Lippincott Williams & Wilkins. (2006) ISBN:0781779308. Read it at Google Books - Find it at Amazon • 7. Yan CH, Wong JW, Yip DK. Bilateral knee lipoma arborescens: a case report. J Orthop Surg (Hong Kong). 2008;16 (1): 107-10. Pubmed citation • 8. Coll JP, Ragsdale BD, Chow B et-al. Best cases from the AFIP: lipoma arborescens of the knees in a patient with rheumatoid arthritis. Radiographics. 2011;31 (2): 333-7. doi:10.1148/rg.312095209 - Pubmed citation • 9. Vilanova JC, Barceló J, Villalón M et-al. MR imaging of lipoma arborescens and the associated lesions. Skeletal Radiol. 2003;32 (9): 504-9. doi:10.1007/s00256-003-0654-9 - Pubmed citation • 10. Sanamandra SK, Ong KO. Lipoma arborescens. Singapore Med J. 2015;55 (1): 5-10. Free text at pubmed - Pubmed citation
- 19. Thank you
Editor's Notes
- Chemical shift artifact or misregistration is a type of MRI artifact. It is a common finding on some MRI sequences, and used in MRS. Chemical shift is due to the differences between resonance frequencies of fat and water. fat resonates at a slightly lower frequency than water. Since the slice position depends on the frequency of the spins, the "fat image" is shifted compared to the "water image". The slice thickness is larger than the shift of the water and fat images making it difficult to detect the effect on routine imaging
- Primary synovial chondromatosis (also known as Reichel syndrome), is a benign monoarticular disorder of unknown origin that is characterised by synovial metaplasia and proliferation resulting in multiple intra-articular cartilaginous loose bodies of relatively similar size 4th or 5th decades of life characterised by proliferative chondroid nodules of the synovium knee (up to 70%) multiple small, well-defined, juxta-articular nodules of uniform size are observed. CT may be able to confirm that the loose bodies are intra-articular T1: intermediate to low signal T2: high signal gradient echo (GE): will show blooming artefact
- Primary synovial chondromatosis (also known as Reichel syndrome), is a benign monoarticular disorder of unknown origin that is characterised by synovial metaplasia and proliferation resulting in multiple intra-articular cartilaginous loose bodies of relatively similar size 4th or 5th decades of life characterised by proliferative chondroid nodules of the synovium knee (up to 70%) multiple small, well-defined, juxta-articular nodules of uniform size are observed. CT may be able to confirm that the loose bodies are intra-articular T1: intermediate to low signal T2: high signal gradient echo (GE): will show blooming artefact
- PVNS is a rare benign proliferative condition affecting synovial membranes of joints, bursae or tendons resulting from possibly neoplastic synovial proliferation with villous and nodular projections and haemosiderin deposition The histology of PVNS can look similar to some aggressive neoplasms (rhabdomyosarcoma, synovial sarcoma, epithelioid sarcoma) early to middle age (2nd to 5th decades) Erosions are often well seen on CT. Calcification is very rare MRI is the best approach showing the mass like synovial proliferation with lobulated margins MRI typically shows masslike synovial proliferation with lobulated margins. diffuse form or limited to a well-defined single nodule in the localised form with low signal intensity due to haemosiderin deposition. 1: low to intermediate signal T1 C+ (Gd): variable enhancement T2 low to intermediate signal some areas of high signal may be present likely due to joint fluid or inflamed synovium STIR: predominantly high signal 2 GE: low and may demonstrate blooming
- PVNS is a rare benign proliferative condition affecting synovial membranes of joints, bursae or tendons resulting from possibly neoplastic synovial proliferation with villous and nodular projections and haemosiderin deposition The histology of PVNS can look similar to some aggressive neoplasms (rhabdomyosarcoma, synovial sarcoma, epithelioid sarcoma) early to middle age (2nd to 5th decades) Erosions are often well seen on CT. Calcification is very rare MRI is the best approach showing the mass like synovial proliferation with lobulated margins MRI typically shows masslike synovial proliferation with lobulated margins. diffuse form or limited to a well-defined single nodule in the localised form with low signal intensity due to haemosiderin deposition. 1: low to intermediate signal T1 C+ (Gd): variable enhancement T2 low to intermediate signal some areas of high signal may be present likely due to joint fluid or inflamed synovium STIR: predominantly high signal 2 GE: low and may demonstrate blooming