Primary Ewing's Sarcoma/Primitive Neuroectodermal Tumor of Kidney with Caval Involvement in a Pregnant Woman.

In this article, we report the case of a woman in whom was found an abdominal mass during pregnancy and who underwent nephrectomy and extraction of the emboli after delivery. The kidney had a volume of 15 × 10 × 8 cm and pathological diagnosis was primary Ewing's sarcoma. The patient was treated with conventional chemotherapy for 1 year after surgery, at which time multiple metastases were found. From this case, we surmise that hormonal changes that occur during pregnancy may accelerate the growth of Ewing's sarcoma of the kidney, suggesting that renal tumors in pregnant women demand serious attention and that anti-cancer treatment should begin as soon as possible.