(A) Microscopically, the renal tumor is composed of polygonal epithelioid cells with abundant eosinophilic cytoplasm, pleomorphic nuclear and hyperchromatic nuclei (hematoxylin and eosin, original magnification 20×), and scattered tumor giant cells and mitotic figures are frequently seen (lower right corner; hematoxylin and eosin, original magnification 40×) . (B) The morphologic features of lung relapses overlapped those of the renal lesion (hematoxylin and eosin, original magnification 20×). (C) and (D) Immunohistochemically, the tumor cells of renal and pulmonary lesions show HMB-45 cytoplasmic reaction. (C) DAB, 20×. (D) DAB, 40×.