Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: Two Unusual Presentations of a Rare Tumor
Figure 2
Twenty-one-year-old female. (a) Bivalved right kidney: gross photography showing islands of tan tissue with hemorrhage and necrotic yellow friable areas (center). (b) Microphotography of the right atrial mass removed from the patient showing islands of small blue cells intermixed with necrotic material and blood. (c) The tumor cells showed positive membranous satins for CD99 (DAB X40). (d) Viable tumor cells positive for CD56, note that the necrotic cells are negative (DAB X40). (e) Synapthophysin was positive in the viable neoplastic cells in a cytoplasm dot-like pattern (DAB X40). (f) Fluorescent microphotography: normal cell lacking t(22; q12), a 2-fusion signal pattern is expected to be seen, reflecting the 2 intact copies of EWSR1. In abnormal cell (circle) with t(22; q12), a 1-fusion, 1 green, 1 orange signal pattern will be expected to occur. This confirmed the EWSR1 fusion transcripts in this peripheral primitive neuroectodermal tumor of the kidney.
