histopathology of bladder and urethra.pdf

The histopathology of the bladder and urethra.

1. HISTOPHATHOLOGY OF THE
BLADDER AND URETHRA

2. URINARY BLADDER
•Hollow muscular elastic organ
that sits on the pelvic floor
posterior to the pubic
symphysis and stores and
expel urine.
•Males: anterior to rectum
•Females: just anterior to the
vagina and uterus

5. URINARY BLADDER
•If full: bladder is spherical and
extends into abdominal cavity
and holds about 500 ml of
urine.
•If empty: bladder lies entirely
within pelvis with shape like
upside-down pyramid.
•Urine exits via the urethra
•Trigone is inside area between
ureters and urethra.

6. BLADDER HISTOLOGIC DESCRIPTION
•4 layers from inside out:
urothelium, lamina propria,
muscularis propria, serosa /
adventitia.
Micrograph showing layers of bladder: urothelium,
lamina propria and muscularis propria.

7. UROTHELIUM
•Urothelium: Three layers of cells.
•Umbrella or apical cells been the superficial layer.
•Formerly called transitional epithelium.
•Pyramid shaped, large and ovoid and it is a binucleated cells.

8. UROTHELIUM SUPERFICIAL CELLS
•Surface outline often overlapping two or more of the underlying cells.
•Superficial cytoplasm is not clearly define its more intensely stained
than the rest of the cytoplasm.
•Luminal surface of the cells appears thickened and more densely
stained.
•Form an impermeable barrier and tight junctions between the cells.

9. UROTHELIUM INTERMEDIATE CELLS
•Multicell layering, depending on the stage of distension.
•Cuboidal to low columnar with well-defined borders.
•Uninucleatedcells with ovoid nuclei.

10. UROTHRLIUM BASAL CELLS
•Single layer in contact with basal lamina.
•Mononucleated with cuboidal cells.
•Cylindrical, can be flat when bladder wall is stretched some
have longitudinal nuclear grooves.

11. The micrograph shows umbrella shaped cells with abundant apical cells.
The basal cells are cuboidal and form a single layer. The lamina propria
is rich in capillaries.

12. LAMINA PROPRIA
•Dense connective tissue containing a rich vascular network, lymphatic
channels, sensory nerve endings, elastic fibersand adipose tissue.
•Thickness varies with the degree of expansion and is generally thinner in
the areas of the trigone and bladder neck.

13. Irregularly smooth muscle fibers. They have a smaller diameter than
muscularispropria.

14. Layer under the urothelium, predominantly consisting
of loose connective tissue and nerves.

15. MUSCULARIS PROPRIA
•3 layers: inner and outer longitudinal layers and a central circular
layer.
•Layers are distinct near bladder neck, elsewhere it is not clearly
define.
•Bladder's body has a higher smooth muscle content compared with the
trigone.

16. Micrograph showing normal bladder histology, with muscularis
propria; organized, thick bundle of muscle (lower right).

17. SEROSA / ADVENTITIA
•Thin connective tissue layer covering the bladder dome and
continuous with the peritoneal layer of the abdominal wall.
•Contains blood vessels of various sizes.
•Adventitia, an outermost layer of loose connective tissue in
areas where there is no serosa.

18. BLADDER PATHOLOGY

19. Urothelial proliferation of uncertain malignant
potential. Thickened urothelium is arranged into
narrow undulating mucosal folds.

20. Papillary or polypoid cystitis. Broad-based polypoid excrescences with
stromal edemaand fibrosis or thin papillae without secondary branching
characterize polypoid cystitis, which is a benign reactive process.

21. Plasmacytoid urothelial carcinoma. Discohesiveindividual cells, with
eccentric nuclei and abundant eosinophilic cytoplasm, characterize
plasmacytoid carcinoma.

22. •Most cases exhibit a variable
percentage of cells with
cytoplasmic vacuoles, with or
without intracellular mucin.
•The absence of extracellular
mucin distinguishes
plasmacytoid urothelial
carcinoma from mucinous
adenocarcinoma with signet-ring
cell features.

23. Mucinous adenocarcinoma with signet-ring features. The abundant
extracellular mucin is characteristic of mucinous adenocarcinoma,
which may have a predominance of signet-ring cells and or other patterns of
admixed mucinous carcinoma.

24. Nested urothelial carcinoma.

25. Micropapillary urothelial carcinoma. Multiple small clusters
of neoplastic urothelial cells in the same lacunar space is a reliable
feature of this subtype and is often associated with lacunar spaces.

26. THE URETHRA
•Smooth muscle with inner mucosa
•Changes from transitional through
stages to stratified squamous near
end.
•Drains urine out of the bladder
and body
•Male: about 20 cm (8) long
•Female: 3-4 cm (1.5) long
•Short length is why females have
more urinary tract infections than
males -ascending bacteria from
stool contamination.

27. MALE URETHRA
•Measures 15 -20 cm in length.
•Urethral sphincter surrounds the urethra.
•Extends from the bladder neck to the inferior fascia of the urogenital
diaphragm.
•Controls urination and discharge of semen into urethra.
•Composed of smooth and striated muscle.
•Divided into prostatic, membranous and penile urethra.

28. PROSTATIC URETHRA
•Extends from the bladder neck through the prostate gland (3 -4 cm)
and lined by urothelium.
•Ejaculatory ducts enter at the posterior wall and most prostatic ducts
empty into the posterior and lateral walls.
•Verumontanum is posterior to the mid prostatic urethra into which the
ejaculatory ducts empty and subsequently join with the prostatic
urethra.

29. The prostatic urethra has an undulated multilayered
epithelium with a large empty lumen.

30. MEMBRANOUS URETHRA
•Extends from the apex of the prostate to the bulb of the penis 1 cm.
•Lined by stratified pseudostratified columnar epithelium similar to
urothelium but lacking umbrella cells.
•Passes through the urogenital diaphragm as it enters the perineum.
•Surrounded by external voluntary sphincter formed by skeletal
muscle of the urogenital diaphragm.

31. PENILE (SPONGY) URETHRA
•Extends through the penis to the urethral meatus opening in the glans
(15 cm).
•Surrounded by the corpus spongiosum
•Bulbourethral (Cowper) glands.

32. The penile urethra has an undulated multilayered epithelium
with a large empty lumen. It is surrounded by corpus
spongiosum with prominent anastomosing vessels.

33. •Divided into 3 regions.
•Bulbar urethra: spans the bulb of the penis, lined by stratified
or pseudostratified columnar epithelium.
•Pendulous urethra: spans the pendulous penis (shaft), lined by
stratified or pseudostratified columnar epithelium.
•Fossa navicularis: dilated portion in the glans, lined by
nonkeratinizing squamous epithelium.

34. FEMALE URETRA
•The female urethra is short 2.5 to 4 cm long and empties at the vulva
2–3 cm posterior to the clitoris.
•The external sphincter muscle is located at the proximal portion of the
urethra.

35. HISTOLOGY OF THE FEMALE
URETHRA
•Epithelium
•The lumen of the proximal female urethra is lined with
urothelium.
•In the middle is columnar epithelium, and the distal urethra is
lined with stratified squamous epithelium.

36. •Lamina propria
•The lamina propria is rich in blood vessel.
•Especially in the distal urethra, numerous glands are located
in the lamina propria.

37. MALE AND FEMALE URETHRA

38. URETHRA PATHOLOGY

39. Male penile urethra, squamous cell
carcinoma in situ within periurethral glands.

40. Male penile urethra, HPV+ high risk ISH in squamous
cell carcinoma.

41. Non-invasive high grade urothelial carcinoma in
a female.
Invasive high grade urothelial carcinoma in a female.

42. Primary urethral squamous cell carcinoma with necrosis.

43. Polypoid mass is lined by normal appearing urothelium and
composed of urethritis cystica.

44. •The glands of the urethritis
cystica and glandularisare
lined by columnar epithelial
cells.
•With pale to eosinophilic
cytoplasm and inconspicuous
nucleoli.
•Eosinophilic contents are
present in the glandular
lumens.