An aggressive course of Xp11 translocation renal cell carcinoma in a 28-year-old man.

Cases of renal cell carcinoma (RCC) associated with Xp11 translocations are rare and are reported predominantly in children. We report a case of a young man who developed an aggressive Xp11 translocation RCC. A 28-year-old man presented with back pain, fever and macroscopic hematuria. Computed tomography of the abdomen showed a heterogeneous mass in the left kidney. Left radical nephrectomy was performed. Hematoxylin-eosin staining revealed nested and papillary architecture, clear and eosinophilic cytoplasm and vesicles with prominent nucleoli. Immunohistochemical evaluation revealed that the tumor cells showed nuclear labeling for TFE3 protein. On the basis of these findings, the case was diagnosed as Xp11 translocation RCC. This tumor massively recurred and led to the patient's death 2 years after the initial diagnosis. The utility of immunohistochemistry using antibodies against TFE3 in RCC occurring in young adults may be necessary for accurate diagnosis.