Dr. Roopam Jain, Professor & Head, Dept. of Pathology & Blood Bank

1. Urothelial
(Transitional Cell)
Bladder Tumours
DR. ROOPAM JAIN
PROFESSOR & HEAD, PATHOLOGY

2. TUMOURS
• Majority of lower urinary tract tumours are epithelial.
• Both benign & malignant tumours occur; the latter being more common.
• About 90% of malignant tumours of the lower urinary tract occur in the
urinary bladder, 8% in the renal pelvis and remaining 2% are seen in the
urethra or ureters.

3. TUMOURS OF THE BLADDER
• The tumours of urinary bladder are divided into epithelial & non-
epithelial (uncommon).
• Thus, epithelial tumours are the main tumours, vast majority of which
are of transitional cell type (urothelial) tumours

4. WHO classification of urinary bladder tumours

5. Urothelial (Transitional Cell)
Bladder Tumours
• More than 90% of bladder tumours arise from transitional epithelial
(urothelium) lining of the bladder.
• Bladder cancer comprises about 3% of all cancers.
• Most of the cases appear beyond 5th decade of life
• 3-times higher preponderance in males than females

6. Urothelial (Transitional Cell) Bladder Tumours
ETIOPATHOGENESIS
• 1. Smoking
• 2. Industrial occupations
• 3. Schistosomiasis
• 4. Dietary factors
• 5. Local lesions
• 6. Drugs
• 7. Prior irraditation

7. Urothelial (Transitional Cell) Bladder Tumours
ETIOPATHOGENESIS
• Several cytogenetic abnormalities have been seen in bladder cancer.
These include several mutations:
• fibroblast growth factor receptor 3,
• p53,
• RB gene
• p21 gene.
• These mutations are associated with higher rate of recurrences and
metastasis.

8. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES - Grossly
• Urothelial tumours may be single or multiple.
• About 90% of the tumours are papillary (non-invasive or invasive),
whereas the remaining 10% are flat indurated (non-invasive or invasive)
(Fig).
• Most common location in the bladder is lateral walls, followed by
posterior wall and region of trigone.
• The papillary tumours have free floating fern-like arrangement with a
broad or narrow pedicle.
• The non-papillary tumours are bulkier with ulcerated surface (Fig). More
common locations for either of the two types are the trigone, the region
of ureteral orifices and on the lateral walls

9. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES
• Th e WHO and ISUP (International Society of Urologic Pathology), in 1998
have proposed histologic criteria to categorise urothelial tumours into
• Papillomas (exophytic, inverted),
• Carcinoma in situ (CIS),
• Papillary urothelial neoplasms of low malignant potential
(PUNLMP)
• Urothelial carcinoma (low grade and high grade).

10. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES
Gross patterns of epithelial bladder tumours

11. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES
Gross patterns of epithelial bladder tumours

12. Carcinoma urinary bladder
The mucosal surface shows papillary tumour
floating in the lumen (arrow)

13. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES - Histologically
Histologic criteria for classifying urothelial
tumours as per WHO/ISUP

14. Urothelial (Transitional Cell) Bladder Tumours
MORPHOLOGIC FEATURES - Histologically
Histologic criteria for classifying urothelial
tumours as per WHO/ISUP

15. Urothelial (Transitional cell) carcinoma, low grade.
There is increase in the number of layers of epithelium in an
orderly manner and slight loss of polarity.
The cells show slight nuclear enlargement and mild variation in
nuclear size and shape and infrequent mitosis.

16. OTHER VARIANTS
• Squamous cell carcinoma comprises about 5% of the bladder
carcinomas.
• Adenocarcinoma of the bladder is rare.
• Small cell carcinoma has morphologic resemblance with small cell
carcinoma of the lung or other neuroendocrine carcinomas and has a
worse outcome.

17. STAGING OF BLADDER CANCER
• The clinical behaviour and prognosis of bladder cancer can be assessed
by the following simple staging system:
• Stage 0: Carcinoma confined to the mucosa.
• Stage A: Carcinoma invades the lamina propria but not the muscularis.
• Stage B1: Carcinoma invades the superficial muscle layer.
• Stage B2: Carcinoma invades the deep muscle layer.
• Stage C: Carcinoma invades the perivesical tissues.
• Stage D1: Carcinoma shows regional metastases.
• Stage D2: Carcinoma shows distant metastases.

18. Non-epithelial Bladder Tumours
• Mesenchymal tumours of the bladder are less
common and may be
• Benign
• Malignant.

19. Non-epithelial Bladder Tumours
BENIGN
• Benign mesenchymal tumour of the bladder is uncommon
• but most common is leiomyoma.
• Other less common examples are neurofibroma, haemangioma & granular
cell myoblastoma.

20. Non-epithelial Bladder Tumours
MALIGNANT
• Rhabdomyosarcoma is the most frequent malignant mesenchymal
tumour. It exists in 2 forms:
• Adult form
• occurring in adults over 40 years of age
• resembles the rhabdomyosarcoma of skeletal muscle.
• Childhood form
• occurring in infancy and childhood
• appears as large polypoid, soft, fleshy, grapelike mass and is also called
sarcoma botryoides or embryonal rhabdo myosarcoma.
• It is morphologically characterised by masses of embryonic mesenchyme
consisting of masses of highly pleomorphic stellate cells