title: Spectrum of Lesions Affecting the Renal Pelvis and Pelviureteric Junction: A 13-Year Retrospective Analysis.
abstract: BACKGROUND
  Both, the renal pelvis and the ureter, are affected by developmental, reactive and neoplastic disorders, though rare in incidence.
  
  
  OBJECTIVE
  This series of cases were analysed to study the clinicopathological characteristics of the common and comparatively rare lesions involving the renal pelvis and pelviureteric junction.
  
  
  METHODS
  A retrospective collection of 476 nephrectomies and pelviureteric junction resections, received over a period of 13 years from 2001 to 2013 was done. The patients' clinical details were obtained and the histopathological findings reviewed. The lesions were classified into non-neoplastic and neoplastic categories.
  
  
  RESULTS
  Primary involvement of the renal pelvis and pelviureteric junction was seen in 105 of 476 specimens. The mean age was 54.5 years with a male to female ratio of 2.2:1. The non-neoplastic lesions accounted for 76.2% of cases with a majority being pelviureteric junction obstruction due to inflammation induced fibromuscular hypertrophy (68.6%) causing hydronephrosis. Urothelial carcinomas were encountered in 20% of the cases. A majority of the urothelial carcinomas were infiltrative (81%) and high grade (71%) tumours.
  
  
  CONCLUSIONS
  Renal pelvis, a conduit to propel urine, can be the site for numerous disorders. Non-neoplastic lesions were more common than neoplasms. Pelviureteric junction obstruction due to inflammation induced fibromuscular hypertrophy was the commonest lesion in our study. In the neoplastic category, urothelial carcinoma was most common. However, rare lesions such as hamartomatous fibroepithelial polyp, Von Brunn's nests, flat urothelial hyperplasia and intramuscular haemangioma of upper ureter at the pelviureteric junction were encountered along with occasional cases of tuberculosis and squamous cell carcinomas.
authors.affiliation: Professor, Department of Pathology, Kasturba Medical College , Mangalore, Manipal University, Karnataka, India .
authors.forename: Hema
authors.initials: H
authors.lastname: Kini
authors.affiliation: Assistant Professor, Department of Pathology, Kasturba Medical College , Mangalore, Manipal University, Karnataka, India .
authors.forename: Hanaganahalli Basavaiah
authors.initials: HB
authors.lastname: Sridevi
authors.affiliation: Assistant Professor, Department of Pathology, Kasturba Medical College , Mangalore, Manipal University, Karnataka, India .
authors.forename: Pooja Kundapur
authors.initials: PK
authors.lastname: Suresh
authors.affiliation: Professor, Department of Urology, Kasturba Medical College Hospital , Ambedkar circle, Mangalore, Manipal University, Karnataka, India .
authors.forename: Laxman Prabhu Gurupur
authors.initials: LP
authors.lastname: Guni
authors.affiliation: Professor, Department of Pathology, Melaka Manipal Medical College , Manipal, Manipal University, Karnataka, India .
authors.forename: Shaila
authors.initials: S
authors.lastname: Bhat
authors.affiliation: Associate Professor, Department of Pathology, Kasturba Medical College , Mangalore, Manipal University, Karnataka, India .
authors.forename: Jyoti Ramanath
authors.initials: JR
authors.lastname: Kini
keywords: Hydronephrosis; Obstruction; Pelviureteric junction; Urothelial carcinomas