Clinicopathologic Features of Translocation Renal Cell Carcinoma.

Background: Translocation renal cell carcinomas (TFE3 RCC) are associated with variable genetic rearrangements of the TFE3 gene on chromosome Xp11.2. Translocation tumors represent 1% to 5% of all cases of RCC, with the greatest frequency among children and young adults. We sought to characterize the clinicopathologic features of translocation RCC at a Middle Eastern institution.

Materials And Methods: The clinical and pathologic data from a single institution were retrospectively reviewed. A total of 14 patients with translocation RCC had been diagnosed from 2005 to 2014. The outcome measures included patient characteristics, clinical manifestations, pathologic features, treatment outcomes, cancer-specific survival, and progression-free survival.

Results: The mean age at diagnosis was 35 years. Of the 14 patients, 5 were female. Translocation RCC was an incidental diagnosis for all but 2 of the 14 patients. The mean tumor size was 9 cm; 1 patient had bilateral tumors, and 3 presented with positive lymph nodes. Three patients underwent partial nephrectomy. Three patients had developed metastasis at 4 months, 5 months, and 3 years after diagnosis. One patent had died 4 months after surgery and one had died 21 months after surgery (both of metastases). The disease-free survival rate was 71% at a mean follow-up of 31 months.

Conclusion: Translocation RCC is a rare and potentially aggressive subtype of kidney cancer. An overall survival of > 3 years has been noted, unless metastasis is present at diagnosis.