[Multiple Recurrences in Perirenal Fatty Tissue 10 Years after Enucleation for Treatment of T1a Renal Cell Carcinoma : A Case Report].

A 71-year-old man underwent simple enucleation for T1a renal cell carcinoma of the left kidney 10 years ago, and, the capsule of the tumor was injured during that surgery. The histopathological diagnosis of the tumor was papillary renal cell carcinoma type1 pT1a, G2 and the surgical margin was negative. Eight years after the surgery, computed tomography (CT) scan imaging showed a mass 13 mm in diameter which was adjacent to the left kidney. In the following year, the mass had grown to 22 mm in diameter. Thus it was suspected as local recurrence of renal cell carcinoma. Magnetic resonance imaging revealed multiple tumors in the left perirenal fatty space and positron emission tomography CT showed abnormal uptake in the same lesions with a maximal standardized uptake value of 3.2. We diagnosed multiple local recurrences of renal cell carcinoma and planned open radical nephrectomy and extirpation of perirenal fat including tumors entirely. The histopathological diagnosis of the tumor was papillary renal cell carcinomas type 1, Fuhrman grade 2＞3. The patient had no recurrence or metastases 10 months after the surgery. It is possible that the tumor cells were disseminated during the first surgery due to an injury to the capsule of the tumor and resulted in multiple local recurrences.