Clear Cell Sarcoma of Kidney : Morphologic Patterns
Morphologic Patterns: Clear cell sarcoma of kidney (CCSK) displays diverse architectural patterns that often coexist in varying proportions within the same tumor. The patterns result from altered morphology of tumor cells within the cords or septae and do not imply biologically distinct cell types. The presence of multiple architectural patterns can mimic other pediatric renal neoplasms and make the diagnosis challenging. The histologic patterns have no prognostic significance. Various morphologic patterns and their frequencies in CCSK is as follows: Classic (90%), myxoid (50%), sclerosing (35%), cellular (26), epithelioid with trabeculae or acini (13%), palisading (11%), spindle cell (7%), storiform (4%), and anaplastic (2.6%). Occasionally, a pattern not seen in the primary tumor may be present in the metastasis. This image shows myxoid (top left), spindle (top right), sclerosing (bottom right), and classic patterns (bottom left).