Rapidly progressing renal cell carcinoma associated with Xp11.2 translocations: a case report

INTRODUCTION: Renal cell carcinoma associated with Xp11.2 translocations is frequently reported in children, but adult-onset is rare. Here, the case of an adult male who developed a renal cell carcinoma associated with Xp11.2 translocations is presented. CASE PRESENTATION: A 38-year-old Asian man presented with left back pain and macroscopic hematuria. Computed tomography revealed a left renal tumor (T3N2M0), and a left radical nephrectomy was performed. Hematoxylin-eosin staining revealed papillary architecture and clear or eosinophilic cytoplasm, and the diagnosis of renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusion was made by the immunohistochemical determination of transcription factor E3 protein. In spite of adjuvant therapy with α-interferon, a recurrent tumor was found in his left lung by computed tomography three months after the nephrectomy. Interleukin-2, tyrosine kinase inhibitors and mammalian target of rapamycin inhibitors showed no effect on tumor progression. CONCLUSIONS: Renal cell carcinomas associated with Xp11.2 translocations have an aggressive clinical course in adults. Strict diagnosis using the immunohistochemistry of transcription factor E3 protein is important to predict the prognosis of such patients and new strategies need to be determined to treat patients with these tumors