Imaging of tumors and tumor-like lesions of the knee

Abstract

Tumors and tumor-like lesions of the knee are common conditions. Because the synovial membrane covers a large part of the knee, tumors and tumor-like lesions of the knee are mostly synovial. Magnetic resonance imaging (MRI) plays a major role in the assessment and characterization of these lesions. However, the diagnostic approach of these lesions must be performed systematically. First, the lesion must be precisely located, and then the anatomical structure involved must be determined. Finally, clinical background that includes the age of the patient, frequency of the disease and, if any, associated signs as well as MRI characteristics must be analyzed. In this review, we describe the anatomy of the knee and its compartments and provide a description of the main tumors and tumor-like lesions of the knee. We present a diagnostic approach based on the location within the knee of the lesions and the anatomical structures involved.

Location, Clinical Presentation, Diagnostic Algorithm and Open vs. Arthroscopic Surgery of Knee Synovial Haemangioma: A Report of Four Cases and a Literature Review

“…It is non-invasive and non-irradiating and usually allows three-dimensional localization, although occasionally, as in our series, a tumor mass may not be identified ( 3 , 47 ). However, the features of low or intermediate intensity compared to muscles on T1-weighted sequences and high intensity on T2-weighted or fat-suppressed sequences are not specific to haemangioma ( 28 , 58 ). Fatty fibrous septa can be seen within the lesion in some cases ( 57 ).…”

“…The clinical presentation is non-specific, with symptom onset usually occurring in childhood and young adulthood, although it has been described at later ages, probably due to delayed diagnosis. Various imaging modalities have been used, but all are non-specific, and there is no clear diagnostic algorithm ( 2 , 4 , 9 , 13 , 18 , 25 , 28 – 30 , 32 , 33 , 38 , 45 , 48 , 50 , 55 , 57 , 58 ).…”

Pigmented Villonodular Synovitis Mimicking an Acute Septic Hip in an Eight-Year-Old Male

“…Findings suggestive of PVNS include T1 and T2 hypointensity of the mass, as well as “blooming artifact” resulting in pseudoenlargement of the mass and corresponding with hemosiderin deposits. The differential diagnosis based on imaging alone, primarily from adult literature, details localized synovial hemangioma, hemophilic arthropathy, synovial sarcoma, and chronic tophaceous gout [ 6 ]. In our case, MRI was not obtained because of the acute presentation and logistical challenges involved in obtaining an MRI in a reasonable time frame.…”

Fat Chance for Hidden Lesions: Pictorial Review of Hoffa's Fat Pad Lesions

“…Upon imaging, a lipoma follows fat signal intensity on all sequences (►Fig. 16), whereas fibrolipoma may have a variegated appearance, depending upon the fibrotic content. The treatment of fibrolipomas involves surgical excision along with their pseudocapsule.…”