Other bladder tumours
- Lesion
Not all bladder cancers are urothelial: chronic irritation, the urachus, neuroendocrine cells and soft tissue give other tumours.
What it is
Squamous cell carcinoma arises in chronically irritated, metaplastic urothelium; where Schistosoma haematobium is endemic (Egypt, sub-Saharan Africa) it is common. Adenocarcinoma arises from the urachus at the dome, from exstrophy or from intestinal metaplasia. Small cell carcinoma is a high-grade neuroendocrine tumour. Mesenchymal tumours include benign leiomyoma, embryonal rhabdomyosarcoma (sarcoma botryoides) of young children and leiomyosarcoma of adults. Secondary tumours invade from the cervix, uterus, prostate and rectum.
Structure
- Squamous: keratin pearls and intercellular bridges in an ulcerated, infiltrative mass; eggs with granulomas in schistosomiasis.
- Adenocarcinoma: glands, often mucinous or signet ring cells.
- Sarcoma botryoides: polypoid mucosa with a dense cambium layer of small primitive cells beneath the epithelium.
Non-urothelial bladder tumours
| Tumour | Setting | Feature |
|---|---|---|
| Squamous cell carcinoma | Schistosomiasis, chronic irritation | Keratinizing; arises in squamous metaplasia |
| Adenocarcinoma | Urachal remnant, exstrophy, glandular metaplasia | Dome tumours, mucin |
| Small cell carcinoma | Older adults, smokers | Neuroendocrine markers; aggressive |
| Mesenchymal tumours | Children (rhabdomyosarcoma), adults (leiomyoma, leiomyosarcoma) | Polypoid or intramural masses |
Clinical notes
- In regions where S. haematobium is endemic, bladder cancer arises earlier and is mainly squamous.
- Hematuria in a toddler with a grape-like mass protruding from the urethra suggests embryonal rhabdomyosarcoma.
Test yourself
Think of the answer, then tap the question to see it.
Which bladder cancer type is associated with schistosomiasis?
Squamous cell carcinoma.
Where does urachal adenocarcinoma arise?
At the dome of the bladder, from remnants of the urachus.
What is sarcoma botryoides?
Embryonal rhabdomyosarcoma forming grape-like polypoid masses, usually in young children.
Elsewhere in DurgiPedia
Connections
Microorganisms1
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: About Schistosomiasis (Centers for Disease Control and Prevention, 2024); Bladder Cancer (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.