MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): a multicenter correlative MRI-pathology study of 21 cases and literature review.

Autor: De Beuckeleer, L. H., De Schepper, A. M., Vandevenne, J. E., Bloem, J. L., Davies, A. M., Oudkerk, M., Hauben, E., Van Marck, E., Somville, J., Vanel, D., Steinbach, L. S., Guinebretière, J. M., Hogendoorn, P. C. W., Mooi, W. J., Verstraete, K., Zaloudek, C., Jones, H., Guinebretière, J M, Hogendoorn, P C
Zdroj: Skeletal Radiology; Apr2000, Vol. 29 Issue 4, p187-195, 9p
Abstrakt: Objective: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts).Design and Patients: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study.Results: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody.Conclusions: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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