American Urological Association - Primary Bladder Adenocarcinoma
Primary Bladder Adenocarcinoma
- 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.
- 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.