t(6; 11) renal cell carcinoma. A case report successfully diagnosed by using fluorescence in situ hybridization

INTRODUCTION: Definitive diagnosis of translocation renal cell carcinoma is challenging. We herein experienced a case of translocation(6;11) renal cell carcinoma, successfully diagnosed by using fluorescence in situ hybridization. CASE PRESENTATION: During the follow‐up of a 21‐year‐old man with Crohn's disease, computed tomography revealed a 40‐mm mass in the right kidney. Since imaging could not exclude malignancy, needle biopsy was performed. The histological diagnosis from the biopsy specimen was renal cell carcinoma, but histological typing had not been done adequately. A laparoscopic partial nephrectomy was then performed. Transcription factor EB immunoreactivity was positive, transcription factor EB rearrangement was shown by break apart and fusion fluorescence in situ hybridization. As a result, a definitive diagnosis of t(6; 11) renal cell carcinoma was made. There has been no recurrence for 5 years. CONCLUSION: Transcription factor EB immunohistochemistry and fluorescence in situ hybridization are useful diagnostic tools for renal tumors of young generation.