[A case of collecting duct carcinoma originating from renal cyst].

In December 2003, a 32-year-old man underwent puncture for right renal cyst at a clinic. Since puncture fluid was dark red color in spite of negative cytology, he was being followed, but after a while he did not show up for further examination. In November 2007, he revisited the clinic due to low-grade fever. Computed tomographic findings showed an enlarged cystic mass with a solid component invading the liver and lymph node swelling. He underwent right radical nephrectomy combined with partial liver resection and lymphadenectomy. Histological findings showed collecting duct carcinoma associated with clear cell carcinoma directly invading the liver with lymph node metastasis (pT4N2M0). Although he underwent 4 cycles of gemcitabine-cisplatin therapy and alfa interferon injection 3 times a week thereafter as adjuvant setting, multiple liver metastasis occurred 15 months after surgery. He died of cancer 31 months after surgery in spite of molecular targeted therapy including sorafenib and sunitinib.