Weekly Case

Title : Case 549

Age / Sex : 46 / M


Chief complaint: Right knee pain for five years

What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case. (Please submit only one answer)

Courtesy: Byeong Seong Kang, Department of Radiology, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea


Diagnosis:

Synovial hemangioma



Discussion



Findings:


1) Plain radiography


-Increased radiopacity of infrapatellar fat


2) MR


-Axial fat-suppressed T2-weighted image: a lobular-shaped mass with heterogeneously hyperintense signal intensity


-Sagittal T1-weighted image: isointense relative to skeletal muscle


-Sagittal, enhanced T1-weighted image: homogeneous intense enhancement


 


Differential Diagnosis:


Synovial hemangioma


Synovial sarcoma


 


Discussion:


Synovial hemangioma is a rare benign vascular malformation that usually affects children and young adults and occurs predominantly in the knee. Patients usually present with joint pain, swelling, and spontaneous hemarthrosis. Conventional radiographs of a patient with synovial hemangioma often demonstrate a nonspecific soft-tissue mass. Phleboliths are not uncommon. On T1-weighted MR images, synovial hemangioma appears hypo- or isointense to muscles. Large venous hemangiomas may cause high signal intensity on T1-weighted sequences caused by slow blood flow. On T2- or fat-suppressed T2-weighted MR images, hemangiomas show hyperintense areas. Low-signal intensity linear structures seen throughout the lesion on T2-weighted images are believed to represent fibrous septa or vascular channels. Large lesions may show heterogeneous enhancement after intravenous administration of a gadolinium chelate.


 


References:



  1. Sheldon PJ, Forrester DM, Learch TJ. Imaging of intraarticular masses. Radiographics. 2005;25:105-19.

  2. Larbi A, Viala P, Cyteval C, Snene F, Greffier J, Faruch M, et al. Imaging of tumors and tumor-like lesions of the knee. Diagn Interv Imaging. 2016;97:767-77.

  3. Sasho T, Nakagawa K, Matsuki K, Hoshi H, Saito M, Ikegawa N, et al. Two cases of synovial hemangioma of the knee joint: Gd-enhanced image features on MRI and arthroscopic excision. Knee. 2011;18:509-11.



Correct Answer
Total applicants 22 Correct answers 7
Name Institution
김동환 군의관, 전문의
이지현 병무청, 전문의
박준동 뿌리병원, 전문의
이영선 전문의
김태형 전문의
박선영 한림대학교 성심병원, 전문의
김보람 전공의


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