Urological Pathology Flashcards
What are urinary calculi? What is the epidemiology of urinary calculi?
Crystal aggregates that form in the renal collecting ducts.
May be deposited anywhere in the urinary tract.
Lifetime incidence 15%.
Males three times more likely to be affected than females.
What are stones in urinary calculi made of?
Calcium Oxalate (Weddellite) – 75%
Magnesium Ammonium Phosphate (Struvite) – 15%
Uric Acid – 5%
What are calcium oxalate stones related to?
Calcium oxalate stones are related to hypercalciuria.
- Absorptive hypercalciuria: Excessive calcium absorption from gut.
- Renal hypercalciuria: Impaired absorption of calcium in proximal renal tubule.
- Hypercalcaemia: Primary hyperparathyroidism.
Rare
What are triple stones?
Magnesium ammonium phosphate stones are also known as ”triple stones”. Form as a consequence of infection with urease-producing organisms (Proteus sp.).
Ammonia alkalinises urine – precipitation of magnesium ammonium phosphate salts follows. Triple stones can become very large indeed.
What are Staghorn Calculi made of?
Magnesium ammonium phosphate
What is this?
Triple stones
What are uric acid stones?
Uric acid stones may form in patients with hyperuricaemia (Gout). Rapid cell turnover.
Most patients do not actually have hyperuricaemia or increased uric acid excretion in urine.
Believed to be due to tendency to produce slightly acidic urine.
What are complications associated with urinary calculi?
Small stones that stay in the kidney may be largely asymptomatic: Otherwise detected during investigation of haematuria or recurrent urinary tract infection.
Small stones that drift out of the kidney may become impacted and cause colic: Pelvi-ureteric junction, pelvic brim, vesico-ureteric junction.
Large stones tend to stay in the kidney: Obstruction, risk of infection, chronic renal failure.
What are papillary adenomas?
Benign epithelial kidney tumour composed of papillae and/or tubules.
- By definition, 15mm or less in size.
- Well-circumscribed.
- Trisomy 7, Trisomy 17, Loss of Y chromosome.
Frequent incidental finding in nephrectomies and at autopsy, especially in chronic kidney disease, acquired cystic renal disease.
What is this?
Papillary adenoma
What are renal oncocytomas?
Benign epithelial kidney tumour composed of oncocytic cells:
- Well-circumscribed
- Usually sporadic
- Can be seen in Birt-Hogg-Dubé syndrome
Usually an incidental finding.
What is this?
Renal oncocytoma
What is this?
Renal oncocytoma
What are angiomyolipomas?
Benign mesenchymal kidney tumour composed of thick-walled blood vessels, smooth muscle and fat:
- Derived from perivascular epithelioid cells
- Mostly sporadic
- Can be seen in tuberous sclerosis
What are the signs and symptoms of angiomyolipomas?
Usually an incidental finding.
Larger tumours (> 4cm) may present with flank pain, haemorrhage, shock.
What is this?
Angiomyolipoma
What are renal cell carcinomas?
Malignant epithelial kidney tumour.
Accounts for 2% of cancers worldwide.
More common in developed countries.
10 per 100,000 men, 3 per 100,000 women.
What are risk factors for renal cell carcinomas?
Smoking
Hypertension
Obesity
Long-Term Dialysis
Genetic Syndromes – von Hippel Lindau
What are signs and symptoms of renal cell carcinoma?
Half of cases present with painless haematuria.
Most of the remaining cases are detected incidentally on imaging.
Small proportion present with metastatic disease.
What are the various subtypes of renal cell carcinoma?
Clear Cell Renal Cell Carcinoma (70%)
Papillary Renal Cell Carcinoma (15%)
Chromophobe Renal Cell Carcinoma (5%)
Remaining 10% are various rare subtypes
What are clear cell renal cell carcinomas?
Epithelial kidney tumour composed of nests of clear cells set in a delicate capillary vascular network.
Appears grossly as a golden yellow tumour with haemorrhagic areas.
Genetically shows loss of chromosome 3p.
What is this?
Clear Cell Renal Cell Carcinoma
What are papillary renal cell carcinoma?
Epithelial kidney tumour composed of papillae and / or tubules.
- By definition, more than 15mm in size.
- Genetically shows trisomy 7, trisomy 17 and loss of Y chromosome.
- Subdivided into two types based on morphology.
Grossly appears as a fragile, friable brown tumour.
What is this?
Papillary renal cell carcinoma
What is this?
Papillary renal cell carcinoma
What are chromophobe renal cell carcinoma?
Epithelial kidney tumour composed of sheets of large cells that display distinct cell borders, reticular cytoplasm and a thick-walled vascular network.
Shows variable genetic aberrations.
Grossly appears as a well-circumscribed solid brown tumour.
What is this?
Chromophobe renal cell carcinoma
What is the prognosis of renal cell carcinomas?
Five year survival across all tumour types is 60%.
Staging and Grading are most important prognostic factors.
ISUP Nuclear Grade (1-4) applies to clear cell and papillary renal cell carcinoma.
For clear cell renal cell carcinoma there is also a risk progression index.
Leibovich Risk Model (low risk, intermediate risk, high risk).
What is a nephroblastoma?
Also known as Wilm’s Tumour.
Malignant triphasic kidney tumour of childhood.
- Blastema (small round blue cells)
- Epithelial
- Stromal
Typically presents as an abdominal mass in children aged 2-5 years old.
1 in 8,000 – second most common childhood malignancy.
95% of cases show favourable histological features with excellent prognosis.
What are urothelial carcinoma?
Also known as Transitional Cell Carcinomas.
Group of malignant epithelial neoplasms arising in urothelial tract.
- Bladder
- Renal Pelvis
- Ureters
Very common.
What are risk factors for urothelial carcinomas?
Smoking
Aromatic amines
What are the signs and symptoms of urothelial carcinomas?
Most present with haematuria.
What are the three main subtypes of urothelial carcinomas?
Non-Invasive Papillary Urothelial Carcinoma
Infiltrating Urothelial Carcinoma
Flat Urothelial Carcinoma in-situ
What are non-invasive papillary urothelial carcinomas?
Appear as frond-like growths. Divided into low grade and high grade based on nuclear atypia.
- Low grade tumours have a low risk of progression to invasive disease (<5%).
- High grade tumours carry a higher risk of progression to invasive disease.
Unstable, carry a number of genetic aberrations including in RB and TP53.
What is this?
Non-invasive papillary urothelial carcinoma
What is this?
Non-Invasive Papillary Urothelial Carcinoma
What is this?
Non-Invasive Papillary Urothelial Carcinoma
What are infiltrating urothelial carcinomas and what is treatment dependent on?
Urothelial tumour displaying invasive behaviour.
Wide range of subtypes.
Treatment based on depth of invasion:
- Lamina propria
- Muscularis propria
What are flat urothelial carcinoma in-situ and how do they appear?
May be invisible or appear as a reddish area.
Flat urothelial lesion with unequivocal high grade features.
High risk of progression.
What is benign prostatic hyperplasia?
Benign enlargement of prostate as a consequence of increase in cell number.
Very common – symptomatic in 25% of men by age 80.
Histologically present in 90% of men by age 80.
What is the aetiology of benign prostatic hyperplasia?
Increased oestrogen levels in blood, which rises with age, may induce androgen receptors and stimulate hyperplasia.
Treatment based on alpha blockers and 5⍺-reductase inhibitors as well as transurethral resection.
What are signs and symptoms of BPH?
Presents with “Lower Urinary Tract Symptoms”.
- Frequency
- Nocturia
- Urgency
- Hesitancy
- Poor flow
- Terminal Dribbling
May also present with urinary tract infection, acute urinary retention or renal failure.
What is this?
BPH
What are prostatic adenocarcinomas?
Malignant epithelial prostate tumour. Most common malignant tumour in men.
- 25% of all male cancers
- 1 in 8 men will develop it in their lifetime
Less prominent (but important) cause of cancer-related death. Association with red meat consumption.
5-10x risk increase if first degree relative is also affected
Arises from Prostatic Intraepithelial Neoplasia.
Mutations in PTEN, AMACR, GST-pi, p27 and more.
What are signs and symptoms of prostatic adenocarcinomas?
Usually asymptomatic; usually diagnosed on biopsy following raised serum prostate-specific antigen or digital rectal examination.
May have lower urinary tract symptoms.
Rarely may present with metastatic disease.
Pathological fracture.
What is the Gleason score?
Most powerful prognostic indicator.
A total score is calculated based on how cells look under a microscope, with the first half of the score based on the dominant, or most common cell morphology (scored 1—5), and the second half based on the non-dominant cell pattern with the highest grade (scored 1—5). These two numbers are then combined to produce a total score for the cancer.
What are testicular germ cell tumours?
Tumours of the testis arising from germ cells.
Account for 90% of testicular tumours.
Typically arise in men aged 20-45.
What are risk factors for testicular germ cell tumours?
- Undescended testis (3-5x increased risk)
- Low birth weight / small for gestational age
- Infertility
Malignant tumours arise from Germ Cell Neoplasia in-situ:
- Process likely begins in foetal life
- Amplification of i12p
What are signs and symptoms of testicular germ cell tumours?
Present as painless lump.
10% present with symptoms related to metastasis:
- Back pain
- Cough
- Dyspnoea
How are testicular germ cell tumours classified?
Five histological subtypes.
Single tumour may be purely one subtype or contain a mixture of multiple subtypes.
What is this?
Seminoma
What is this?
Embryonal Carcinoma
What is this?
Post-Pubertal Teratoma
What is this?
Yolk Sac Tumour
What is this?
Choriocarcinoma
What is the management and prognosis of testicular germ cell tumours?
Highly sensitive to platinum-based chemotherapy regimes.
Prognosis excellent.
Five year survival is 98% in most countries.
What are testicular non-germ cell tumours?
Much less common than germ cell tumours:
- Lymphoma
- Leydig Cell Tumour
- Sertoli Cell Tumour
What is lymphoma?
Older men, 5% of all testicular tumours
Highly aggressive; poor survival rates
What are leydig cell tumours?
3% of all testicular tumours.
May present with precocious puberty if pre-pubertal.
Usually benign.
What are sertoli cell tumours?
1% of testicular tumours
90% are benign
What are paratesticular diseases?
Epididymal cyst
Epididymitis
Varicocele
Hydrocele
Adenomatoid Tumour
What is epididymitis?
Usually related to C. trachomatis or N. gonnorrhoeae in men under 35; E. coli in men over 35.
What is a variocele?
Dilated venous plexus.
What is a hydrocele?
Fluid between layers of tunica vaginalis
What is a adenomatoid tumour?
Small tubules lined by mesothelial cells
What are penile diseases?
Lichen Sclerosus/Balanitis Xerotica Obliterans
Zoon’s balanitis
Condylomas: HPV 6 and 11
Peyronie’s Disease
Penile carcinoma
What is Lichen Sclerosus/Balanitis Xerotica Obliterans?
Inflammatory condition that causes phimosis
What is Zoon’s balanitis?
Inflammatory condition that causes red areas.
What is Peyronie’s Disease?
Scarring, inflammation, thickening of corpus cavernosa.
What is penile carcinoma?
Rare, elderly men
Smoking, HPV, chronic Lichen Sclerosus are risk factors.
What are urethral diseases?
Urethritis: N. gonorrhoeae, C. trachomatis
Prostatic Urethral Polyp
Urethral Caruncle
Urethral Carcinoma
Malignant Melanoma: Rare
What are Prostatic Urethral Polyps?
Papillary lesion in prostatic urethra
What are urethral caruncle?
Common lesion at urethral meatus in women.
What are urethral carcinomas?
Rare, more common in women, usually squamous cell carcinoma.
What are scrotal diseases?
Epidermoid Cyst: Common
Scrotal Calcinosis: Rare; may be related to old epidermoid cysts.
Angiokeratomas: Benign vascular lesions
Fournier’s Gangrene: Necrotising fasciitis; mortality of 15-20%.
Scrotal squamous cell carcinoma: Very rare. Historical interest; chimney sweep.
