Ultrasound Evaluation of Masses

Transcription

1 Ultrasound Evaluation of Masses Jon A. Jacobson, M.D. Professor of Radiology Director, Division of Musculoskeletal Radiology University of Michigan Disclosures: Consultant: Bioclinica Advisory Panel: GE, Philips Book Royalties: Elsevier Note: all images from the textbook Fundamentals of Musculoskeletal Ultrasound are copyrighted by Elsevier Inc. Question: tumor or pseudotumor? Pseudotumors: Tendon tear with retraction: Rectus femoris, tibialis anterior Muscle hernia Anomalous muscle: Accessory soleus Extensor digitorum brevis manus Rheumatoid nodule Rectus Femoris Tear: full tear, pseudomass Long Axis Muscle Hernia: anterior tibialis Accessory Soleus Muscle Achilles Transverse 1

2 Rheumatoid Nodules Question: anatomic location? Achilles Joint, tendon sheath, or bursal origin Synovial: benign Gout Osseous origin Aggressive: infection or malignancy Soft tissue origin Variable etiology Outline: Joint Recess Mass arising from a joint is a benign synovial process: Rheumatoid arthritis Pigmented villonodular synovitis Synovial sarcoma: very rarely involves a joint Pigmented Villonodular Synovitis Tibia Talus Longitudinal Sagittal T1w post-gado Outline: Bursa 2

3 Bursa Baker Cyst Mass arising from a bursa Benign synovial process Understand locations of normal bursa Anechoic or hypoechoic Compressible May be complex Example: Baker cyst MG Transverse SM Longitudinal MG Bicipitoradial Bursitis Bicipitoradial Bursitis BT Long Axis to Biceps Sagittal T2w Short Axis to Biceps Axial T2w Bicipitoradial Bursitis Gout: olecranon bursa Humerus Long Axis to Biceps: Lateral Approach Olecranon 3

4 Outline: Tendon Gout Popliteus tendon: knee Patellar tendon: inferior Other tendons Giant cell tumor of tendon sheath Pseudotumor: Tendon tear and retraction Rectus femoris, tibialis anterior Gout: patellar tendon Gout: popliteus P T Femur Tibia T2w T2w Giant Cell Tumor of Tendon Sheath Phalanx Transverse Flexor Tendon Parasagittal Outline: 4

5 Lymph Node Hyperplastic: Oval, hyperechoic hilum, hilar vascular pattern Malignant: Asymmetric thick cortex Round Loss of hyperechoic hilum Variable vascular pattern Lymph Node: reactive Longitudinal color Doppler Lymph Node: reactive B cell Lymphoma : axillary V A Lymphoma X Lymph Node: angiosarcoma metastasis X X X 5

6 Outline: Ganglion Cysts Mass may correspond to a ganglion cyst Hypoechoic Multilocular Not compressible Specific locations Ganglion Cysts Wrist: Dorsal: over scapholunate ligament Volar: between radial artery and FCR Knee: Cruciates, gastrocnemius tendon Hoffa s fat pad Ankle: Tarsal tunnel Radius Ganglion Cyst: dorsal Lunate Capitate Lunate Peroneal Intraneural Ganglion Joint fluid from proximal tibiofibular joint Enters peroneal nerve via articular nerve branches Shown at MR arthrography after exercise Extends proximal via epineurial sheath 1 May also form via tibial nerve 2 Peroneal Intraneural Ganglia 1 Spinner et al. Clin Anatomy 2007; 20:826 2 Spinner et al. Skeletal Radiol 2006; 35:172 From: Spinner et al. Skeletal Radiol 2008;37:1091 From: Spinner et al. Clin Anatomy 2007;20:826 6

7 Intraneural Ganglion Ganglion Cysts >15 cm Differential diagnosis: Parameniscal cyst Paralabral cyst: hip and shoulder Atrophy Asymptomatic Lateral Meniscus: tear and parameniscal cyst Femur Tibia Outline: Subcutaneous Masses Lipoma Fat necrosis Epidermal inclusion cyst : benign versus malignant Lipoma: subcutaneous Oval or oblong Homogeneous Isoechoic to adjacent fat Hyperechoic: With increased fibrous tissue components No internal vascularity Compressible Inampudi et al. Radiology 2004; 233:763 7

8 Lipoma: subcutaneous Lipoma: subcutaneous Lipoma: subcutaneous Lipoma: deep Compression Sonopalpation Variable echogenicity Often ill-defined Often difficult to assess Cannot reliably differentiate from lowgrade liposarcoma! Need MRI Paunipager et al. Insights Imaging 2010; 1:149 Lipoma: intramuscular Liposarcoma: well-differentiated Hypoechoic Looks like a lipoma Need MRI with any suspected deep lipoma! T1w 8

9 Fat Necrosis Pain, palpable, focal Thigh, women No erythema Normal WBC Epidermal Inclusion Cyst: Trauma: implantation of epithelium Congenital Squamous metaplasia Hair follicle obstruction T1w T2w+ FS Gado J Ultrasound Med 2008; 27:1751 Kim et al. Skeletal Radiol 2011; 40:1415 Epidermal Inclusion Cyst Epidermal Inclusion Cyst: ruptured Sagittal T1w Coronal post-gado Outline: Other Masses: malignant Sarcoma Metastasis 9

10 Synovial Sarcoma Tumor Metastasis: Renal Cell Carcinoma Sarcoma: high grade Metastasis Squamous cell carcinoma Note: increased through-transmission (open arrows) Melanoma Hypoechoic mass Usually increased flow on color Doppler Lymph node: Focal cortical enlargement Diffusely abnormal Nazarian et al. AJR 1998; 170:459 Take Home Points Key to differential diagnosis: Specific anatomic location Joint and tendon: benign : unilocular, compressible : multilocular, not compressible Lipoma: subcutaneous, oval, compressible Malignancy: hypoechoic, heterogeneous See for syllabus 10