title: Mantle cell lymphoma presenting as a pelvi-ureteric junction obstruction: a case report.
abstract: BACKGROUND
  Mantle cell lymphoma is one of the several subtypes of non-Hodgkin's lymphoma. Mantle cell lymphoma is the rarest of the subtypes, accounting for about 6% of all non-Hodgkin's lymphoma cases in the United States and Europe. Lymphoid neoplasms of the urinary tract and male genital organs are relatively rare, accounting for less than 5% of extranodal lymphomas. We present a rare case of mantle cell lymphoma infiltrating the ureter causing pelvi-ureteric junction obstruction on tissue diagnosis.
  
  
  METHODS
  A 78-year-old Caucasian woman was referred to our department with right flank pain, pyrexia and features of a urinary tract infection. A nephrostogram revealed a grossly distended right pelvicalyceal system in a pelvi-ureteric junction obstruction pattern. She underwent an elective pyeloplasty after her acute management and the results of histological examination revealed mantle cell lymphoma.
  
  
  CONCLUSIONS
  We describe a rare presentation of mantle cell lymphoma as a pelvi-ureteric junction obstruction. To the best of our knowledge, there has not been any previously published report of the above finding. Our patient had a history of a previous lymphoma but the aim of this manuscript is to highlight a possible presentation rather than determining whether the mantle cell lymphoma was de novo or a transformation from her previous splenic lymphoma with villous lymphocytes.
authors.affiliation: Department of Urology, Worthing Hospital, West Sussex BN11 2DH, UK. n.ishvar@gmail.com.
authors.forename: Ishvar
authors.initials: I
authors.lastname: Naranji
authors.forename: Rhana H
authors.initials: RH
authors.lastname: Zakri
authors.forename: Thomas
authors.initials: T
authors.lastname: Liston