Xp11 Translocation Renal Cell Carcinoma: Delayed but Massive and Lethal Metastases of a Chemotherapy-Associated Secondary Malignancy

A recently described subtype of renal cell carcinoma (RCC) bearing chromosome translocations involving a breakpoint at Xp11 and resulting in gene fusions involving the TFE3 transcription factor gene often presents in the pediatric population. Herein we describe an Xp11 translocation RCC associated with prior exposure to cytotoxic chemotherapy, which massively recurred and led to the patient's death 17 years later. This case highlights the association of these RCCs with prior chemotherapy exposure, the tendency of these RCCs to recur late, their unusual pattern of metastases, and the utility of TFE3 immunohistochemistry in confirming their diagnosis in archival pathologic specimens.