title: Malignancies arising in allograft kidneys, with a first reported translocation RCC post-transplantation: A case series.
abstract: BACKGROUND
  The increased risk of malignancy in the post-renal transplant population has been well documented. Renal carcinoma is more common in this population, usually arising in native kidneys. Rarely, tumors arise in the transplanted kidney. Our case series reports four cases of malignancy in allograft kidneys, one of which is a first reported case of translocation RCC in a transplanted kidney.
  
  
  METHODS
  The renal transplantation database (1584 patients) at St. Michael's Hospital was reviewed for malignancies arising in allograft kidneys: reports and pathology slides were reviewed.
  
  
  RESULTS
  Four cases of malignancies arising in the allograft kidney were identified among our kidney transplant population. One patient developed a high grade urothelial carcinoma in the donor kidney post BK virus infection. The other 3 cases were renal cell carcinomas: one clear cell renal cell carcinoma, one translocation renal cell carcinoma, and one papillary renal cell carcinoma. The translocation renal cell cancer had confirmed TFE3 protein over-expression by immunohistochemistry. Molecular testing of the tumors in all 4 cases identified two separate genetic profiles, favored to represent tumors arising from donor tissues along with infiltrating recipient lymphocytes.
  
  
  CONCLUSIONS
  Previous reports suggested that epithelial malignancies in allograft kidneys are rare. We identified 4 such tumors in 1584 transplant patients. Further, we identified the first reported case of translocation RCC in an allograft kidney. While the rate of malignancy in allograft kidneys is low, screening of the donor kidneys by ultrasound and/or urine cytology may be of use in detecting these lesions.
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Saleeb
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Faragalla
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.
authors.forename: G M
authors.initials: GM
authors.lastname: Yousef
authors.affiliation: Department of Urology, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada. Electronic address: streutkerc@smh.ca.
authors.forename: C J
authors.initials: CJ
authors.lastname: Streutker
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D014178:Translocation, Genetic / Q000502:physiology*; D014184:Transplantation, Homologous
keywords: Allograft; Kidney; Malignancy; Transplantation; Xp11 translocation