Histo: Urology Flashcards
What are urinary calculi?
Crystal aggregates in the renal collecting ducts.
NOTE: lifetime incidence of 15%
List the three main types of urinary tract calculi in order of prevalence.
- Calcium oxalate (Weddelite) - 75%
- Magnesium ammonium phosphate - 15%
- Urate - 5%
List some underlying conditions that can lead to the formation of calcium oxalate stones.
- Absorptive hypercalciuria - excessive calcium absorption from the gut
- Renal hypercalciuria - impaired absorption of calcium in the proximal renal tubule
- Hypercalcaemia (e.g. hyperparathyroidism)
Describe how magensium ammonium phosphate stones are formed.
- Results from infection by a urease-producing organism (e.g. Proteus)
- Ammonia produced by the bacteria alkalinises the urine leading to precipitation of magnesium ammonium phosphate stones
- They can become large (e.g. staghorn calculi)
- NOTE: they are also called triple stones
Which patients are predisposed to the formation of urate stones?
- Gout
- Rapid cell turnover (e.g. chemotherapy)
NOTE: however, most patients with urate stones will not have these risk factors
Where do urinary calculi stones tend to get stuck within the urinary tract?
- Pelvic-ureteric junction
- Pelvic brim
- Vesico-ureteric junction
What are the consequences of large stones within the urinary tract?
- Obstruction
- Risk of infection
- CKD
List three types of benign renal neoplasm.
- Papillary adenoma
- Renal oncocytoma
- Angiomyolipoma
Define papillary adenoma.
- Benign epithelial kidney tumour composed of papillae and/or tubules
- They must be <15 mm in size
- They tend to be well circumscribed
What are the genetic associations of papillary adenomas?
- Trisomy 7 and 17
- Loss of Y chromosome
What is a renal oncocytoma?
- Benign epithelial kidney tumour composed of oncocytic cells
- They are usually well-circumscribed and usually sporadic
NOTE: often an incidental finding
Name a syndrome that is associated with renal oncocytoma.
Birt-Hogg-Dubé syndrome
Describe the histological appearance of oncocytes.
Large cells with pink granular cytoplasm and a prominent nucleolus
What is an angiomyolipoma?
- Benign mesenchymal kidney tumour composed of thick-walled blood vessels, smooth muscle and fat
- Derived from perivascular epitheloid cells
NOTE: often an incidental finding but may cause flank pain, haemorrhage and shock (if >4cm)
Which hereditary condition is associated with angiomyolipoma?
Tuberous sclerosis
list some risk factors for renal cell carcinoma.
- Smoking
- Hypertension
- Obesity
- Long-term dialysis
- Genetic (e.g. von Hippel Lindau)
How does renal cell carcinoma tend to present?
- Painless haematuria
Name the subtypes of renal cell carcinoma in order of prevalence.
- Clear cell renal carcinoma (70%)
- Papillary renal cell carcinoma (15%)
- Chromophobe renal cell carcinoma (5%)
Define clear cell renl carcinoma.
- Epithelial kidney tumour composed of nests of clear cells set in a delicate capillary vascular netwrok
- Grossly apears golden-yellow with haemorrhagic areas
What is a common genetic finding in clear cell renal carcinoma?
Loss of chromosome 3p
Define papillary renal cell carcinoma.
- Epithelial kidney tumour composed of papillae and/or tubules
- By definition >15mm in size
NOTE: this is the malignant counter part of papillary adenoma. They appear grossly as a fragile, friable brown tumour
Describe the histological appearance of the two types of papillary renal cell carcinoma.
- Type 1: composed of a single layer of small and flat cells. You see a lot of islands of cells.
- Type 2: there is stratification (multi-layering) of the cells
NOTE: type 2 tends to have a worse prognosis than type 1
Define chromophobe renal cell carcinoma.
- Epithelial kidney tumour composed of sheets of large cells that display distince cell borders, reticular cytoplasm and a thick-walled vascular network
NOTE: grossly appears as a well-circumscribed solid brown tumour
Describe the histological appearance of chromophobe renal cell carcinoma.
Sharply defined cell borders and a thick vascular network
What is the 5-year survival for renal cell carcinoma?
60% across all types
What grading system is used for clear cell and papillary renal cell carcinoma?
ISUP Nuclear Grade
What risk progression index is used for clear cell carcinoma?
Leibovich risk model
What is Nephroblastoma (Wilm’s tumour)?
Malignant triphasic kidney tumour of childhood:
- Blastema (small round blue cells)
- Epithelial
- Stromal
Typically present with an abdominal mass in children aged 2-5 years
NOTE: 95% have an excellent prognosis
What are the major risk factors for urothelial carcinoma?
Smoking
Aromatic amines
What are the three main subtypes of urothelial carcinoma?
- Non-invasive papillary urothelial carcinoma
- Invasive urothelial carcinoma
- Flat urothelial carcinoma in situ
Describe the macroscopic appearance of non-invasive papillary urothelial carcinoma.
- Appears as frond-like growths
- Can be divided into low or high grade dependent on nuclear atypia
NOTE: high grade tumours have many genetic aberrations (e.g. RB, TB53)
Describe the histological appearance of invasive urothelial carcinoma.
- This is urothelial tumour that has started showing invasive behaviour
- Once urothelial cells to invade, the morphology becomes very diverse (e.g. squamous, adenocarcinoma, sarcoma etc.)
NOTE: treatment is based on the depth of invasion: lamina propria, muscularis propria
What is flat urothelial carcinoma in situ?
High grade lesion in situ (may progress to become invasive)
Define benign prostatic hyperplasia.
Benign enlargement of the prostate gland as a consequence of increased cell number
What is a possible mechanism for the onset of BPH?
Increased oestrogen with ageing induces androgen receptors and stimulates hyperplasia
List some treatment options for BPH.
- 5alpha-reductase inhibitors
- Alpha-blockers
- TURP
How can BPH present?
- LUTS (most common)
- UTI
- Acute urinary retention
- Renal failure
What is the most common malignant tumour in men?
Prostate cancer
What is the precancerous lesion that prostate cancer arises from?
Prostatic intraepithelial neoplasia
List some mutations that are implicated in prostate cancer.
- PTEN
- AMACR
- P27
- GST-pi
What scoring system is used for prostate cancer? Explain how it is calculated.
Gleason score
- Expressed as x + y = z
- Calculated by adding the top two most common patterns/grades seen on histological grading
- Higher scores are associated with poorer prognosis
List some risk factors for testicular germ cell tumours.
- Undescended testicles
- Low birth weight
What is the pre-malignant lesion associated with testicular germ cell tumours?
Germ cell neoplasia in situ
NOTE: this process probably begins in foetal life
Which genetic factor is associated with testicular germ cell tumours?
Amplification of i12p
List the five histological subtypes of testicular germ cell tumours.
- Seminoma
- Embryonal carcinoma
- Post-pubertal teratoma
- Yolk sac tumour
- Choriocarcinoma
Describe the histological appearance of:
- Seminoma
- Embryonal carcinoma
- Post-pubertal teratoma
- Yolk sac tumour
- Choriocarcinoma
-
Seminoma
- Mostly made up of clear cells with a prominent lymphocytic infiltrate
-
Embryonal carcinoma
- High-grade appearance with prominent nucleoli
-
Post-pubertal teratoma
- The tumour is trying to produce a variety of tissues (e.g. keratin, cartilage, glands)
- This is malignant - any component of the tumour can become malignant
-
Yolk sac tumour
- Smaller cells
- Lace-like pattern
- Some pink inclusions
-
Choriocarcinoma
- Made up of two cell types: cytotrophoblasts (clear looking cells) and syncytiotrophoblasts (multinucleated cell)
- NOTE: both components are needed to define choriocarcinoma
How are testicular germ cell tumours treated?
They are highly sensitive to platinum-based chemotherapy
5-year survival: 98%
Name three types of testicular non-germ cell tumours.
- Lymphoma - more in older men, poor prognosis
- Leydig cell tumour - may cause precocious puberty (if pre-pubertal)
- Sertoli cell tumour - 90% benign
What are the causes of epididymitis?
- <35 years = N. gonorrhoea and C. trachomatis
- 35+ years = E. coli
What is an adenomatoid tumour?
Benign tumour consisting of small tubules lined by mesothelial cells
List some types of benign penile diseases.
- Lichen sclerosus/balanitis xerotica obliterans - inflammatory condition that causes phimosis
- Zoon’s balanitis - inflammatory condition that causes red areas
- Condylomas - HPV6 and 11
- Peyronie’s disease - scarring, inflammation and thickening of the corpus cavernosa
List some risk factors for penile carcinoma.
- HPV
- Smoking
- Lichen sclerosus
List and describe some benign diseases of the urethra.
- Urethritis
- Prostatic urethral polyp - papillary lesion in the prostatic urethra
- Urethral caruncle - common lesion at the urethral meatus in women
NOTE: malignant diseases include urethral carcinoma (squamous cell carcinoma) and malignant melanoma
List and describe some diseases of the scrotum.
- Epidermoid cyst (common)
- Scrotal calcinosis
- Angiokeratomas (benign vascular lesions)
- Fournier’s gangrene - necrotising fasciitis of the scrotum and perineu,
- Scrotal squamous cell carcinoma