title: Clinicopathologic outcomes of cystic renal cell carcinoma.
abstract: BACKGROUND
  The purpose of this study was to describe the clinicopathologic characteristics and oncologic outcomes of patients who underwent nephrectomy for cystic renal masses.
  
  
  METHODS
  Using an institutional review board-approved database, we retrospectively reviewed the clinical, pathologic, radiologic, and oncologic outcome data of patients who received nephrectomy for a complex cystic renal mass.
  
  
  RESULTS
  Sixty-one patients were identified who received nephrectomy for a complex cystic lesion. Average age was 64 years. Thirty-nine (64%) patients were male. At the time of resection, 1 (1.6%), 3 (4.8%), 53 (86.8%), and 4 (6.5%) had a Bosniak category II, IIF, III, and IV cystic lesion, respectively. Nineteen (31.1%) patients were initially managed expectantly but underwent surgery because of progression of complexity on follow-up. Mean pathologic tumor size was 3.3 cm (range, 0.7-12 cm). Forty-eight (78.6%) of the lesions were found to be malignant. Thirty-seven (77.1%), 5 (10.4%), 4 (8.3%), and 2 (4.1%) were stage T1a, T1b, T2a, and T3a, respectively. Clear cell was the most common histologic subtype (44%), followed by papillary (21.3%), and unclassified RCC (4.9%). With a mean and median follow-up of 48.4 and 43.0 months, respectively, no patients developed a local or metastatic recurrence. All patients were alive at last follow-up.
  
  
  CONCLUSIONS
  In our series with moderate follow-up, cystic RCCs do not appear to recur or progress regardless of size, histologic subtype, or grade. These findings suggest the malignant potential of cRCCs is significantly less than solid RCCs. Further investigation is required to determine if cRCCs should be classified and managed independently from solid RCCs.
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY. Electronic address: Nicholas.Donin@nyumc.org.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Donin
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mohan
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY.
authors.forename: Hai
authors.initials: H
authors.lastname: Pham
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, NY.
authors.forename: Hersh
authors.initials: H
authors.lastname: Chandarana
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, NY.
authors.forename: Ankur
authors.initials: A
authors.lastname: Doshi
authors.affiliation: Department of Pathology, New York University School of Medicine, New York, NY.
authors.forename: Fang-Ming
authors.initials: FM
authors.lastname: Deng
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Stifelman
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Taneja
authors.affiliation: Department of Urology, New York University School of Medicine, New York, NY.
authors.forename: William C
authors.initials: WC
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000473:pathology* / Q000601:surgery*; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
keywords: Carcinoma; Cystic kidney disease; Neoplasm metastasis; Neoplasm staging; Nephrectomy; Renal cell