Pigmented clear cell sarcoma of soft tissue: an important diagnostic mimic.

Clear cell sarcoma of soft tissue (CCSST) is a rare and aggressive soft tissue tumour associated with tendons and aponeuroses of the lower extremities. Due to its melanocytic differentiation, distinguishing CCSST from melanocytic neoplasms and other pigmented lesions can be challenging. We report a peculiar case of CCSST and discuss the histological, immunohistochemical and molecular features which can aid in accurate diagnosis of this entity. [ABSTRACT FROM AUTHOR]