Differential diagnoses were all ruled out with extensive immunohistochemical analysis, including carcinomas (no cytokeratin or PAX8 staining), especially renal cell carcinoma which can display a similar morphology with large eosinophilic cytoplasm and atypical nucleolated nuclei and similar genetic alteration t(X;17)(p11;q25) [9]. The gene discussed is PAX8; the disease is hereditary clear cell renal cell carcinoma.