Clear Cell Sarcoma of Kidney
The classic morphologic pattern seen in more than 90% of clear cell sarcomas of the kidney consists of nests, cords, and sheets of ovoid, epithelioid, or spindled tumor cells separated by thin fibrous septa containing delicate vasculature (chicken wire appearance). A moderate amount of clear intercellular matrix intervening between the tumor cells gives rise to the "clear cell" appearance. In addition to this classic pattern, numerous other patterns have been noticed in CCSK, including myxoid, sclerosing, cellular, epithelioid, palisading, spindle cell, storiform, and anaplastic. The image shows myxoid pattern with abundance of intercellular myxoid matrix.