Lower Urinary Tract Outline
Lower Urinary tract
•Ureter
•Bladder
•Urethra
Lower Urinary Tract
Lower Urinary Tract:
Several Similar morphological characteristics

In spite of different embryonic origin

All are lined by a special type of transitional
epithelium(Urothelium)(Renal pelves,uretes,bladder
and the proximal urethra)

There are 3-5 layers of epithelial lining in the
Ureters, while the layers in the bladder may be up
to 7 layers.

Lower Urinary Tract
Lower Urinary Tract:
There is a well developed basement
membrane ,a distinct lamina propria as well a
muscularis propria(detrusor muscle fibres)

The Ureters are close to the uterine arteries
in females and may be easily injured at
surgery

Lower Urinary Tract
Lower Urinary Tract:
The ureters insert into the bladder at an oblique
angle creating an anatomic sphinteric mechanism
that prevents Upward reflux of urine .
The orifice of the ureter is usually at the bladder
trigone which is lined by glycogenated squamous
epithelium

The close anatomic proximity of the female genital
tract to bladder increases the incidence of spread of
infection from one tract to the other.

Lower Urinary Tract
Ureter Congenital Anomalies
•2-3% of all biopsies
•Most are not clinically significant
•Ureterovesical junction anomalies often predispose
to VUR.( a common cause of pyelonephritis)
1. Double ureters:
•Derived from a double or split ureteral bud
•Associated with either double renal pelvis or with a
large kidney with bifid pelvis., no significance.
Lower Urinary Tract
2. Ureteroplevic junction obstruction:
•Left ureters>Right
•Boys>girls
•Most common cause of hydronephrosis in
children
Lower Urinary Tract
Inflammation of the ureter (Ureteritis):
•Usually develops as a component of UTI
Tumors of the ureter
•Rare
•Fibroepithelial polyps
•Leimyomas
•Primary malignant tumors are Transitional cell
carcinomas
Lower Urinary Tract
Ureteral obstruction: Clinically important because it can
cause pathology in the kidney. (hydroureters,
hydronephrosis)
•Ureteral stones
•Stricture
•Tumors
•Blood clots
•Neurogenic
•Inflammatory lesions
Lower Urinary Tract
Urinary bladder:
•Bladder diseases are usually a source of distress
and discomfort.
Congenital Anomal1ies
1. Diverticular:
•A pouchlike evagination of the bladder
•Due to a failure of development of the normal
musculature or to urinary tract obstruction
during fetal development.
Lower Urinary Tract
Congenital Diverticular:
•Frequently multiple
•May constitute sites of urinary stasis=>
Infection and calculi formation.
•May also predispose to VUR as a result of
impingement on the ureters
•Carcinomas may also arise within a
diverticular(rare)
Lower Urinary Tract
Bladder Exstrophy:
•Developmental failure of the anterior abdominal wall
and bladder
•The bladder communicates through a larger defect in the
abdominal wall with the surface.
•Increased risk of infection that may spread to the upper
urinary tract or systemic infections.
•Chronic infection often transforms the exposed mucosa
to a stratified Squamous type.
•Surgery corrects the situation.
Bladder Exstrophy
Lower Urinary Tract
Vesicourethral reflux:
•Common
•Also clinically very important
•It is a major contributor to renal infection and
scarring. Especially with regards to pyelonephritis.
•Caused by a shortening of the intravesical portion of
the ureter.=>a more horizontal insertion of the ureters
into the bladder.
Lower Urinary Tract
Urinary Bladder:
Inflammations: Acute and Chronic Cystitis
•Acute Cystitis:
•Gram negative
coliforms;E.Coli,Proteus,Klebsiella and
Enterobacter.
•Commoner in females because of the shorter
urethra. Other non common causes
:T.B,Candida(in immunocompromised),Chlamydia
and Mycoplasma.
Lower Urinary Tract
Acute Cystitis cont:
•Shistosomiasis is a common cause in Egypt and
Sudan
•Cyclophosphamide =>Hemorrhagic cystitis
•Radiation of the bladder=>radiation cystitis.
Morphology
•Mucosal hyperemia, neutrophillic exudates.
Lower Urinary Tract
Chronic Cystitis:
Persistence of infection leads to chronicity
•Similar morphological features apart from the
presence of lymphocytes in the exudates
•The bladder wall shows evidence of fibrosis and
in-elasticity
Variants includes: Follicular cystitis(aggregation
of lymphocytes into lymphoid follicles) and
eosinophilic cystitis(submucosal eosinophils).
Lower Urinary Tract
Presentation of Cystitis:
Triad of:
•Frequency
•Lower abdominal pain
•Dysuria: usually burning pain on
micturition
•Cystitis may also predispose to developing acute
pyelonephritis.
Lower Urinary Tract
Special Cystitis
Interstitial Cystitis:
•Etiology unknown
•Painful chronic cystitis
•Mast cells in the bladder wall.
•Must rule out carcinoma
Malacoplakia
•Related to chronic infection with E.coli or
immunosuppresion.
Lower Urinary Tract
Bladder Malacoplakia:
It represents a bladder inflammatory reaction,
Gross: soft, yellow,raised mucosal plaques.
Histology: Foamy macrophages with occasional giant
cells. There are interspersed lymphocytes.
•Michaelis- Gutman bodies are seen. These are
laminated mineralized concretions resulting from
deposition of calcium in enlarged lysosomes.
Mchaelis –Gutman bodies
Lower Urinary Tract
Neoplasms:
•95% of bladder tumors are of epithelial origin
•Mesenchymal tumors account for the rest.
•Most Epithelial are composed of transitional
epithelium and are known as transitional tumors or
Urothelial tumors. Benign lesion, known as Papillomas
are rare.
•Transitional Cell Carcinomas:
•May be seen anywhere that is lined by
urethelium(renal pelvis to the distal urethra)
Lower Urinary Tract
Transitional cell carcinoma of the Bladder:
Risk factors:
•Smoking
•B-Naphtylamine
•Chronic Cystitis
•Schistosomiasis
•Cyclophosphamide
Carcinoma of the Bladder
:Commoner in male with a 3:1 ratio.
• Presents with painless haematuria
• May also cause CVA pain
• Recurrence after surgery is common
• Prognosis depends on tumor grade,
differentiation and depth of invasion
Carcinoma of the Bladder
Morphology cont:
• Flat
• Papillary
• Low grade
• High grade.
Low grade tumors are papillary and are usually
not invasive tumors. Recurrence after surgery
is common .
Carcinoma of the Bladder
Morphology Cont’D.
• High grade tumor: Usually papillary, but may
be flat. They occupy large area of the bladder
and have a shaggier, necrotic appearance.
• Higher grade tumor would have evidence of
distal metastasis.
Low Grade Urothelial carcinoma, orderly arrangement of
thickened epithelium
High Grade Papillary Carcinoma: Marked Cytologic atypia
with pleocytosis
Papillary Tumor
Lower Urinary Tract
Neoplasms:
Other Carcinomas:
•Squamous cell carcinoma
•Mesenchymal tumors
•Secondary tumors
•Squamous cell carcinoma is seen with
schistosomiasis.(endemic zones Egypt and sudan)