Paratesticular Leiomyosarcoma : Smooth Muscle Actin
Section Editor: Dharam M. Ramnani, MD
Virginia Urology, Richmond, VA, USA
Image Description
Paratesticular leiomyosarcomas, like other soft tissue leiomyosarcomas, show smooth muscle differentiation immunohistochemically. This consists of positivity for smooth muscle actin (shown here), muscle-specific actin, and desmin. Focal positivity for cytokeratin and S-100 protein is seen in a small percentage of cases. Some cases also show CD34 positivity which is an unusual feature.