Pediatric renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion.

Renal cell carcinoma (RCC) in children and young adults is rare and pathologically problematic. RCC can be either hereditary or sporadic and has a guarded prognosis because appropriate management has not been established. A case of RCC in an 11-year-old is reported. The clinical presentation was a right abdominal mass, hematuria, urinary tract infection, and wasting. Radio-logically, the mass was found within the right kidney with calcification and paraaortic lymphadenopathy. The postsurgical diagnosis was Wilms' tumor stage T4N2M0. On gross inspection, the tumor was ill defined, extending across Gerota's fascia and into the ureter lumina. Microscopically, the tumor consisted of malignant epithelial cells with clear and eosinophilic cytoplasm in nested, papillary, and alveolar configuration. Hyaline nodules, psammoma bodies, vascular invasion, capsular invasion, and extension into the ureter were also found. Immunohistochemically, the cells showed strong nuclear immunoreactivity for TFE3. We concluded that this case was an RCC associated with Xp11.2 translocation/TFE3 fusion, Fuhrman grade 3, stage IV.