Keywords:
Arthritides, Diagnostic procedure, MR, Musculoskeletal system, Musculoskeletal joint
Authors:
R. Johnson, R. Chari, R. Chowdhury, R. Mansour, C. McCarthy, J. Teh; Oxford/UK
DOI:
10.1594/essr2016/P-0137
Imaging findings OR Procedure Details
We review a series of 15 cases of lipoma aborescens in multiple sites including the knee (Fig 1-4) and more unusual locations such as the hip (Fig 5) and cubital bursa (Fig 6-8).
The spectrum of imaging findings includes mass-like proliferation of the knee,
which can be mistaken for tumour. It is important to look for underlying conditions such as gout (Fig 9-10),
rheumatoid arthritis and osteoarthritis (Fig 3).
The differential diagnosis includes synovial chondromatosis,
pigmented villonodular synovitis (PVNS),
rice bodies (in rheumatoid arthritis),
venous malformations (with intervening fat) and osseous loose bodies.2 The differentiating feature in lipoma aborecens is however its signal characteristics which are isointense to fat on all sequences.
It should be bright on both T1 and T2,
and supress on the fat saturated sequences.
An intra-articular lipoma would have the same signal characteristics,
however this rare lesion would have a discrete thin,
fibrous capsule.
Treatment is often conservative,
though a synovectomy can be curative if clinically indicated.