title: Gender differences in benign renal masses.
abstract: OBJECTIVE
  To examine gender-specific differences in benign renal tumors.
  
  
  METHODS
  This retrospective study included 135 adult Caucasian patients with 143 benign renal tumors, which were treated surgically at a single institution. Demographics, comorbidity, histology, renal function, and management were compared by gender. A systematic review and meta-analysis of the literature were performed.
  
  
  RESULTS
  A total of 73 women were compared with 62 men. The female-to-male ratio was significantly higher in patients with benign renal tumors than in those with renal cell carcinoma (1.18:1 vs. 0.57:1, p < 0.001). Only 17 % of benign renal tumors were correctly classified by preoperative computed tomography. The most frequently observed histological types were oncocytoma (44 %) and angiomyolipoma (37 %). Angiomyolipoma occurred more than twice as often in women than in men (72 vs. 28 %), while oncocytoma was more frequently found in men (59 vs. 41 %, p = 0.001). Men with benign renal tumors were older (p = 0.002) and had higher body mass indices (p = 0.019), higher comorbidity indices (p < 0.001), lower ECOG performance status (p < 0.001), and smaller tumors (p = 0.045). No differences were seen in pack years, mode of diagnosis, bilaterality, renal function, use of laparoscopic surgery, and the rate of radical nephrectomy. In the meta-analysis of 9,665 renal tumors, women had a 2.55-fold increased chance of benign pathology and a greater chance of angiomyolipoma (OR 4.66) than men.
  
  
  CONCLUSIONS
  This study demonstrated several gender-specific differences in benign renal tumors, especially in the histological types. Despite this, clinical-pathological features and management of benign renal tumors in men and women appear more alike than different.
authors: Department of Urology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors: Julian
authors: J
authors: Mauermann
authors: Michela
authors: M
authors: de Martino
authors: Matthias
authors: M
authors: Waldert
authors: Andrea
authors: A
authors: Haitel
authors: Hans Christoph
authors: HC
authors: Klingler
authors: Mesut
authors: M
authors: Remzi
authors: Tobias
authors: T
authors: Klatte
mesh_terms: D018249:Adenoma, Oxyphilic / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018207:Angiomyolipoma / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D015995:Prevalence; D012189:Retrospective Studies; D012737:Sex Factors