• Users Online: 633
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
CASE REPORT
Year : 2015  |  Volume : 42  |  Issue : 1  |  Page : 45-48

Lipoma arborescens: is it the cause or effect?


1 Department of Radiodiagnosis, J N Medical College, Aligarh, India
2 Department of Orthopedics, J N Medical College, Aligarh, India
3 Department of Pathology, J N Medical College, Aligarh, India

Date of Submission01-Jan-2014
Date of Acceptance29-Oct-2014
Date of Web Publication22-Apr-2015

Correspondence Address:
Saifullah Khalid
Assistant Professor, Department Of Radiodiagnosis, Jawaharlal Nehru Medical College and Hospital, AMU, Aligarh - 202 002, Uttar Pradesh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1110-161X.155652

Rights and Permissions
  Abstract 

Lipoma arborescens is benign villous lipomatous proliferation of the synovium. The fronds-like masses are non-neoplastic fatty deposits on the synovium. The word arborescens is a Latin term meaning 'tree-forming' or 'tree-like'. This article presents two cases of young adults who presented with pain and swelling around knee joint and were diagnosed on the basis of characteristic MRI findings, and hence signifies the role of MRI in diagnosing the cause of inflammatory synovitis in young patients. In addition, MRI helped in deciding the management of these patients. There was significant symptomatic improvement seen on follow-up, which further helps to strengthen the hypothesis that underlying lipoma arborescens could be a rare underlying cause for undiagnosed inflammatory synovitis in young adults.

Keywords: inflammatory synovitis, knee effusion, lipoma arborescens, MR


How to cite this article:
Khalid S, Asif N, Afrose R, Faizan M, Khalid M, Sherwani RK. Lipoma arborescens: is it the cause or effect?. Egypt Rheumatol Rehabil 2015;42:45-8

How to cite this URL:
Khalid S, Asif N, Afrose R, Faizan M, Khalid M, Sherwani RK. Lipoma arborescens: is it the cause or effect?. Egypt Rheumatol Rehabil [serial online] 2015 [cited 2019 Oct 16];42:45-8. Available from: http://www.err.eg.net/text.asp?2015/42/1/45/155652


  Introduction Top


Lipoma arborescens (LA) is a rare, idiopathic synovial disorder characterized by frond-like, non-neoplastic, fatty deposition on the synovium. In most cases, it is idiopathic in nature or seen in association with degenerative joint disease or rheumatoid arthritis [1],[2],[3] . Recently, it has been suggested that LA could be associated with undiagnosed inflammatory synovitis, especially in young adults [4],[5],[6] . This report of these two cases stresses the possibility of an association between LA and inflammatory synovitis and highlights the role of MRI in helping to reach the diagnosis and decide proper management. The importance of correct diagnosis is that these patients undergo arthroscopic synovectomy or radiosynovectomy using 185 MBq yttrium-90 colloid rather than receiving oral medication.


  Case report Top


Case 1

A 25-year-old male patient presented with pain and swelling around right knee joint. There was no history of trauma to the knee or recent episode of fever. He had a similar episode 2 months earlier and was treated with oral medications, nature of which is not known. Clinical examination revealed suprapatellar fullness; however, there was no joint tenderness or redness of the overlying skin. There was neither similar medical family history nor any complaints in other axial or sacroiliac joints.

A plain radiography of knee joints was advised, which showed neither bony or articular abnormality nor any periarticular osteopenia. Suprapatellar fullness was noted. A diagnostic aspiration of the synovial fluid turned out to be inflammatory in nature (white blood cell count 8600/mm 3 ; polymorphs 93%; lymphocytes 2%, and mononuclear cells 5%). Rheumatoid factor, anticyclic citrullinated peptide antibodies, and antinuclear antibody tests were negative. A provisional diagnosis of inflammatory synovitis was considered. He was advised MRI knee to look for any synovial or intra-articular pathology. MRI showed frond-like intra-articular synovial masses, which were hyperintense on both T1W and T2W sequences suggestive of fatty origin. This was confirmed on fat-saturation sequences, when the lesion became hypointense. There was no evidence of underlying bone erosions or degenerative changes. Gadolinium-enhanced MRI showed synovial enhancement with mild thickening ([Figure 1]). Thus, a diagnosis of LA with inflammatory synovitis was made. The patient underwent arthroscopy, which showed pinkish-white frond-like proliferation along synovial lining in suprapatellar region ([Figure 2]). Therapeutic synovectomy was performed and histopathological examination showed them to be composed of mature adipocytes with chronic inflammatory cells ([Figure 3]). The patient was last examined clinically as well by high-frequency ultrasound at 5-month follow-up. He has no recurrence or further complaints in other joint. There was no positive finding on ultrasound imaging.
Figure 1 Axial T1 weighted MRI (a, b) shows suprapatellar effusion with frond-like synovial masses. Fat-saturated axial T2W MRI (c, d) confirms the fatty nature of synovial masses. Gadolinium-enhanced axial and sagittal T1W fat-suppressed MRI (e, f) shows no enhancement of the fatty synovial mass but enhancement of the synovial lining.



Click here to view
Figure 2 Arthroscopy image shows pinkish– white frond-like proliferation along synovial lining in suprapatellar region.



Click here to view
Figure 3 Villous projections show accumulation of mature adipose tissue that is covered by layers of hyperplastic synovial cells. Focal chronic inflammatory infiltrate and dilatation of capillaries are present (hematoxylin and eosin stain, ×40 and ×400 magnification).



Click here to view


Case 2

An 18-year-old female patient presented with acute onset of pain and swelling around left knee joint. There was no history of recent episode of fever or trauma. Mild suprapatellar fullness was noted with no joint tenderness or redness of the overlying skin. Radiography ruled out any bony, articular abnormality or periarticular osteopenia ([Figure 4]). Rheumatoid factor, antinuclear antibody, and anti-citrullinated peptide antibodies were also negative. Diagnostic synovial fluid aspiration was inflammatory in nature. MRI knee was advised, which showed villous projection arising from the synovium of fatty nature confirming LA. Gadolinium-enhanced MRI showed mild synovial thickening with enhancement ([Figure 5]). The patient underwent therapeutic arthroscopic synovectomy. Histopathological examination showed that the villi were composed of mature fat tissue and chronic inflammatory cells. The patient was last seen clinically at 7-month follow-up. She has progressed well with no further complaints in the joint.
Figure 4 Radiograph of the knee joint (AP and lateral view) shows no bony or articular abnormality. Suprapatellar fullness is seen. AP, anteroposterior.



Click here to view
Figure 5 Axial T2 weighted (a, c) shows joint effusion with frond-like synovial masses of fat intensity. Coronal STIR MRI (b) confirms the fatty nature of synovial masses. Gadolinium-enhanced axial T1W fat-suppressed MRI (d) shows enhancement of the synovial lining.



Click here to view



  Discussion Top


LA usually involves single joint [3],[5],[7] , and bilateral and multifocal disease is relatively less common [7],[8] . By far, the most common joint to be involved is knee joint [9] . Rarely, disease in other joints such as ankle, shoulder, and elbow has also been reported [3] . In the knee, suprapatellar fossa is most commonly involved. The disease is commonly seen in the third to fifth decade of life. There is no sex predilection reported with this disease condition. Common presentation is with painless, slowly progressive swelling of the joint with intermittent and/or recurrent effusion and restricted range of movement.

LA can be an underlying cause for undiagnosed inflammatory synovitis as suggested by Ragab et al. [4] . Oni and Oni [5] suggested that chronic synovitis could be an underlying cause for LA Santiago et al. [6] reported polyarticular LA associated with chronic inflammatory synovitis mimicking rheumatoid arthritis. The significance of this association is change in management of these patients as they will undergo arthroscopic synovectomy.

The investigation of choice is MRI [10],[11] . LA follows signal characteristics of fat on MRI with fat-saturation sequence confirms the diagnosis. Thus, the disease can be confidently diagnosed on MRI, helping in planning proper management and follow-up, if needed. Vilanova et al. [11] in their study reported that the most commonly associated MR pathology in the knee was joint effusion (100%) followed by degenerative changes (87%) and meniscal tear (72%). The histopathological examination of the excision biopsy confirms the diagnosis [8] .

The differential diagnoses to be considered are pigmented villonodular synovitis, synovial osteochondromatosis, chronic rheumatoid arthritis, synovial lipoma, and synovial hemangioma [9] . Pigmented villonodular synovitis characteristically shows low signal intensity on all pulse sequences due to hemosiderin deposition, whereas synovial osteochondromatosis and chronic rheumatoid arthritis show low-to-intermediate signal intensity on T1W sequence. The closest mimic is synovial lipoma, which follows same signal intensity on MRI but presents as a focal mass of fat in and around Hoffa's fat pad. The synovial hemangioma shows foci of low signal intensity corresponding to phleboliths.

The definite treatment is either an open or an arthroscopic synovectomy [12] . There are reports of successful treatment using 185 MBq yttrium-90 colloid [13] . Follow-up is usually advised to rule out recurrence, which is rare. We experienced difficulty in follow-up by MR imaging because of the cost strain and availability. We performed follow-up by clinical examination and by ultrasound. Ultrasonography can be a good imaging modality in follow-up because it is widely available, cheap, and in experienced hands easy to perform. We are of the opinion that ultrasound should have been used at the time of diagnosis. This helps in follow-up by an imaging method in addition to the clinical examination.


  Conclusion Top


These two cases of young adults further signify the role of MRI in undiagnosed inflammatory synovitis in young patients. MRI helped in reaching the diagnosis as well as changed the management. The significant symptomatic improvement seen on follow-up further helps to strengthen the hypothesis that underlying LA could be a rare underlying cause for inflammatory synovitis in young adults.


  Acknowledgements Top


Conflicts of interest

None declared.

 
  References Top

1.
Al-Ismail K, Torreggiani WC, Al-Sheikh F, Keogh C, Munk PL Bilateral lipoma arborescens associated with early osteoarthritis. Eur Radiol 2002; 12 :2799-2802.  Back to cited text no. 1
    
2.
Coll JP, Ragsdale BD, Chow B, Daughters TC. Best cases from the AFIP: lipoma arborescens of the knees in a patient with rheumatoid arthritis. Radiographics. 2011; 31 :333-337.   Back to cited text no. 2
    
3.
In Y, Chun KA, Chang ED, Lee SM. Lipoma arborescens of the glenohumeral joint: a possible cause of osteoarthritis. Knee Surg Sports Traumatol Arthrosc 2008; 16 :794-796.   Back to cited text no. 3
    
4.
Ragab Y, Emad Y, Banakhar A. Inflammatory synovitis due to underlying lipoma arborescens (gadolinium-enhanced MRI features): report of two cases. Clin Rheumatol 2007; 26 :1791-1794.   Back to cited text no. 4
    
5.
Oni DB, Oni G. Inflammatory synovitis due to underlying lipoma arborescens. Clin Rheumatol 2008; 27 :1079.   Back to cited text no. 5
    
6.
Santiago M, Passos AS, Medeiros AF, Sá D, Correia Silva TM, Fernandes JL. Polyarticular lipoma arborescens with inflammatory synovitis. J Clin Rheumatol 2009; 15 :306-308.   Back to cited text no. 6
    
7.
Weits T, Tania BH. Lipoma arborescens of the knee. JBR-BTR, 2010; 93 : 166-167.   Back to cited text no. 7
    
8.
Cil A, Atay OA, Aydingöz U, Tetik O, Gedikoðlu G, Doral MN. Bilateral lipoma arborescens of the knee in a child: a case report. Knee Surg Sports Traumatol Arthrosc 2005; 13 :463-467.   Back to cited text no. 8
    
9.
Khalid S, Faizan M, Jamal F, Feraz S, Ahmad I. Recurrent suprapatellar fullness and synovial frond-like masses on knee MRI. Oman Med J 2014; 29 :305.   Back to cited text no. 9
    
10.
Martín S, Hernández L, Romero J, Lafuente J, Poza AI, Ruiz P, Jimeno M. Diagnostic imaging of lipoma arborescens. Skeletal Radiol 1998; 27 :325-329.   Back to cited text no. 10
    
11.
Vilanova JC, Barceló J, Villalón M, Aldomà J, Delgado E, Zapater I. MR imaging of lipoma arborescens and the associated lesions. Skeletal Radiol 2003; 32 :504-509.  Back to cited text no. 11
    
12.
Al-Shraim MM. Intra-articular lipoma arborescens of the knee joint. Ann Saudi Med 2011; 31 :194-196.   Back to cited text no. 12
    
13.
Erselcan T, Bulut O, Bulut S, Dogan D, Turgut B, Ozdemir S, Goze F Lipoma arborescens; successfully treated by yttrium-90 radiosynovectomy. Ann Nucl Med 2003; 17 :593-596.  Back to cited text no. 13
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Case report
Discussion
Conclusion
Acknowledgements
References
Article Figures

 Article Access Statistics
    Viewed1838    
    Printed16    
    Emailed0    
    PDF Downloaded146    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]