Introduce the etiologic spectrum of soft-tissue masses about the knee with emphasis on the most common entities.
Discuss the role of conventional radiography (CR),
ultrasonography (US) and magnetic resonance (MR) imaging and Positron Emission Tomography - Computed Tomography (PET-CT) in the diagnosis and the management of soft tissue tumors of the knee.
Develop a systematic diagnostic imaging-based approach for the work-up of a suspected soft-tissue mass.
Soft-tissue tumors and tumorlike lesions are encountered often in daily radiologic practice.
the majority of these lesions are cystic and benign.
There is a broad differential for soft-tissue lesions about the knee.
The list includes tumorlike lesions as synovial cyst (Baker cyst,
pigmented villonodular synovitis (focal or diffuse),
myositis ossificans and tumoral calcinosis.
Benign soft-tissue tumors in this particular location includes synovial lipoma,
extraskeletal chondroma and osteochondroma.
clear-cell carcinoma and pleomorphic sarcoma are the malignant...
Imaging findings OR Procedure Details
Classification and pathology of soft-tissue tumors and tumor-like lesions about the knee:
Definiton: a herniation or continuation of the synovial membrane through the joint capsule
POPLITEAL CYST / BAKER CYST is the most commonly recognized,
results from communication between knee joint and gastrocnemius – semimembranosus bursa
Fluid filled mass – US/CT/MRI
May have septations
Can have solid components if complicated (rupture) with hemorrhage,
dissection or superimposed infection
Contrast enhancement of rim/septae
Contrast enhancement of solid components of complicated cysts
By systematically using clinical history,
mineralization on radiographs,
appearance on US and signal intensity characteristics on MR images,
one can (a) determine the diagnosis for the subset of determinate lesions that have characteristic clinical and imaging features and (b) narrow the differential diagnosis for lesions that demonstrate indeterminate characteristics.
If a lesion cannot be characterized as a benign entity,
the lesion should be reported as indeterminate,
and the patient should undergo biopsy to exclude malignancy.
Soft-Tissue Tumors and Tumorlike Lesions: A Systematic Imaging Approach.Radiology; 2009,253: 297–316.
Imaging of synovial chondromatosis with radiologic-pathologic correlation.Radiographics 2007;27(5):1465-88.
Pigmented villonodular synovitis: radiologic-pathologic correlation.
Localized nodular synovitis of the knee: MR imaging appearance and clinical correlates in 21 patients.
AJR Am J Roentgenol 2003; 181: 539–543.
Ana Mª Crespo Rodríguez,
Hospital Clínico San Carlos,
Formerly Hospital Universitario Puerta de Hierro