Home Education AUAUniversity Education Products & Resources Pathology for Urologists Urinary Bladder Non-urothelial Carcinomas Primary Bladder Adenocarcinoma

Primary Bladder Adenocarcinoma

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  • There are 2 general types of adenocarcinomas in the bladder:
    • Those arising from the urachus (urachal adenocarcinoma, ~1/3), and those arising from the bladder itself (~2/3) (image A).
  • Primary adenocarcinoma of the bladder overall is rare, and accounts for only 1% of bladder carcinomas.
  • Suggested to arise from intestinal metaplasia of the urothelium.
  • Nonfunctioning bladder, chronic irritation, obstruction, exstrophy are risks.

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  • Histology:
    • Tumor should be purely gland forming (distinguish from urothelial carcinoma with glandular differentiation).
    • Several morphologic patterns such as enteric (looks like colorectal adenocarcinoma!)
      (image B), (image C), & (image D), adenocarcinoma not otherwise specified, mucinous, signet ring cell, hepatoid or mixed (2 or >patterns).
    • Signet ring cell type may diffusely invade the bladder wall (similar to linitis-plastica in gastric carcinoma).
  • Should always include metastasis or extension from an intestinal adenocarcinoma, before making the diagnosis.
  • Immunohistochemistry: expresses enteric marker CDX2, but unlike colorectal adenocarcinoma has more CK7+ and is nuclear β-catenin-.
  • Staging is the same for urothelial carcinoma.
  • Prognosis is poor with 5-year survival rate of 18-47%, and high proportion presents with higher stage including up to 40% with metastasis at the time of diagnosis.