[Breast cancer metastasized to the pararenal fat 26 years after mastectomy : a case report].

A 66-year-old woman was referred to our hospital with a right renal tumor in October 2010. In 1984, she underwent a mastectomy because of left breast cancer. In 2006, she underwent a lobectomy because of right lung cancer. A follow-up computed tomography of the lung cancer revealed a right renal tumor which extended to the right quadratus lumborum muscle. An exploratory laparotomy was performed and the tumor was found to be malignant by an intra-operative examination. Then, we performed a right radical nephrectomy together with the excision of quadratus lumborum muscle. Pathological examination revealed breast cancer metastasized to the pararenal fat. We could not find any invasion of the tumor into the renal parenchyma. We followed her for 2 months after the operation without any evidence of recurrence, but she suddenly expired due to an unrelated accident.