title: Clear cell renal cell carcinoma with osseous metaplasia: a case report.
abstract: BACKGROUND
  Osseous metaplasia is a rare histologic feature not often associated with renal cell carcinoma; there are only 14 reported cases and just four associated with the clear cell variant. We report the case of a 48-year-old female who presented with diffuse abdominal pain.
  
  
  METHODS
  We reviewed the case of woman who underwent a robotic assisted partial nephrectomy for an enhancing renal mass. Histologic analyses and immunostains were reviewed by multiple pathologists.
  
  
  RESULTS
  CT imaging revealed a 1.8 cm irregular enhancing exophytic mass with calcifications. The patient subsequently underwent robotic assisted laparoscopic partial nephrectomy. The final pathologic diagnosis was clear cell carcinoma with metaplastic bone formation.
  
  
  CONCLUSIONS
  While the prognostic significance of bone metaplasia occurrence in renal cell carcinoma is controversial, such that can safely be managed with partial nephrectomy.
authors.affiliation: Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611-3008, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hartman
authors.forename: Brian T
authors.initials: BT
authors.lastname: Helfand
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Dalton
mesh_terms: D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery; D008679:Metaplasia; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D009999:Ossification, Heterotopic / Q000473:pathology*; D012371:Robotics