Track

Clinical Studies

Abstract

While best known for its use in differentiating atypical, pigmented lesions, PRAME immunohistochemistry expression in soft tissue tumors has not been thoroughly characterized. Few studies have been performed to characterize the immunohistochemistry of PRAME in soft tissue tumors and used PRAME clone QR005 to examine different soft tissue tumors and mimics. This is the first study to use clone EPR20330 in a similar context. Using this clone, we stained 38 cases of soft tissue tumors including neoplasms arising from the dermis, appendages of the skin, and vascular neoplasms. The EPR20330 clone of PRAME was found to be positive in various high-grade tumors. Even though PRAME was not found to be completely specific, positive PRAME staining was generally correlated with the high-grade nature of the neoplasms. The most specific staining pattern found in the vascular neoplasms revealed that all lesions lacked PRAME expression by immunohistochemistry, except within high-grade and malignant vascular neoplasms such as angiosarcoma. This expression could be an important diagnostic aid as the differentiation of benign and proliferative lesions with low-grade malignant neoplasms can be a diagnostic challenge. This confirms findings similar to other studies and demonstrates generalizability through use of an alternative PRAME clone. In addition to being able to evaluate PRAME expression in different cutaneous soft tissue tumors, the discovery of PRAME expression in high-grade tumors identifies a potential additional therapeutic target. The findings of this study highlight the need for further research to elucidate PRAME's expression and usefulness as a therapeutic target.