title: Tubulocystic renal cell carcinoma in the left kidney: a case report.
abstract: BACKGROUND
  Tubulocystic renal carcinoma is a rare tumor and has been recently recognized as a neoplastic entity. We report a case of tubulocystic renal carcinoma in the left kidney and present a review of relevant literature.
  
  
  METHODS
  A 35-year-old Japanese woman visited our hospital with the chief complaint of left-sided back pain. Computed tomography revealed a hemorrhagic cyst (size, 7×8cm) in the upper pole of her left kidney. Approximately 3 years after the initial diagnosis, she complained of left-sided back pain again. Magnetic resonance imaging revealed an enlarged left renal cyst (size, 10×12cm) with a slightly enhanced cystic wall. The tumor was clinically diagnosed as a renal cell carcinoma in the cT2N0M0 stage, which arose from the cyst wall; therefore, left nephrectomy was performed. On histological examination, the tumor showed circumscribed proliferation with cystically dilated tubules. The tubules and cysts were lined by a single layer of flat, hobnail, and cuboidal cells. Immunohistochemical analysis revealed that the tumor cells were strongly positive for E-cadherin and P504S.
  
  
  CONCLUSIONS
  Examination of more cases of tubulocystic renal carcinoma is required to better understand the biology of this tumor and to ascertain its prognosis.
authors: Yusuke
authors: Y
authors: Ishibashi
authors: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifucho, Hirosaki 036-8562, Japan. goodwin@cc.hirosaki-u.ac.jp.
authors: Takuya
authors: T
authors: Koie
authors: Naoki
authors: N
authors: Fujita
authors: Tendo
authors: T
authors: Satoh
authors: Jotaro
authors: J
authors: Mikami
authors: Shingo
authors: S
authors: Hatakeyama
authors: Chikara
authors: C
authors: Ohyama
authors: Yuki
authors: Y
authors: Tobisawa
authors: Tohru
authors: T
authors: Yoneyama
mesh_terms: D000328:Adult; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D007685:Kidney Tubules, Collecting / Q000473:pathology*; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000473:pathology*