Bilateral tubulocystic renal cell carcinomas in diabetic end-stage renal disease: first case report with cytogenetic and ultrastructural studies

Tubulocystic renal cell carcinoma (TC-RCC) is a rare renal tumor composed of well-differentiated tubules and cysts lined by neoplastic cells with eosinophilic cytoplasm and prominent nucleoli. The origin of the tumor cells is still controversial. TC-RCC typically arises unilaterally. Involvement of both kidneys by multifocal TC-RCC has not been reported. In this study we report the first case of bilateral and multifocal TC-RCC. Immunohistochemical, cytogenetic and ultrastructural studies suggest TC-RCC is closely related to papillary RCC.