title: Osseous metaplasia within a urothelial bladder cancer nodal metastasis: a case report.
abstract: BACKGROUND
  Osseous metaplasia within bladder cancer is extremely rare and, to our knowledge, has not been previously reported within a urothelial bladder carcinoma (UBC) nodal metastasis.
  
  
  METHODS
  A 78-year-old man underwent radical cystoprostatectomy because of high-grade pT2 UBC. Pathology revealed a high-grade pT4aN2 UBC with osseous metaplasia into a massively metastatic lymph node but not into the primary bladder tumor.
  
  
  CONCLUSIONS
  Based independently on its location, this finding warrants a careful differential diagnosis with sarcomatoid bladder tumors and is likely to be a marker of tumor aggressiveness, thus recommending aggressive treatment.
authors.forename: Luigi
authors.initials: L
authors.lastname: Cormio
authors.forename: Francesca
authors.initials: F
authors.lastname: Sanguedolce
authors.forename: Paolo
authors.initials: P
authors.lastname: Massenio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Fino
authors.forename: Oscar
authors.initials: O
authors.lastname: Selvaggio
authors.forename: Pantaleo
authors.initials: P
authors.lastname: Bufo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Carrieri
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000556:secondary*; D003937:Diagnosis, Differential; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008679:Metaplasia / Q000473:pathology; D009999:Ossification, Heterotopic / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*; D019459:Urothelium / Q000473:pathology*