Urinary neoplasia Flashcards
What types of neoplasia affect the kidney?
what is the most common malignant tumour of the kidney?
Normally malignant neoplsia
* Most common in middle-aged to older animals
* No breed predilection has been found
most common malignant tumour is renal carcinoma
* usually, it is unilateral, located at one pole of the kidney, and well demarcated
* size varies from microscopic to several times that of the normal kidney
* metastasise early to various organs; the opposite kidney, lungs, liver, and adrenals are involved most commonly
What renal malignant tumour arise from vestigial embryonic tissue?
what is the predisposition?
what are the characteristics?
Nephroblastomas
* They are seen in young animals and, in dogs, are most commonly diagnosed at < 1 yr of age
* There is no breed predilection
* Males are affected twice as commonly as females
* Nephroblastomas are usually unilateral but are occasionally bilateral
* They can grow to immense size; it is not uncommon to have virtually the entire abdomen occupied by tumour
* Metastasis may occur to regional lymph nodes, liver, and lungs
what transitional epithelium neoplasia can you get in the kideny?
what are the other renal malignanct renal neoplasias?
Transitional cell carcinomas - malignant
Other primary malignant renal neoplasms are uncommon and include haemangiosarcomas, fibrosarcomas, leiomyosarcomas, and squamous cell carcinomas
most common multicentric tumour involving the kidneys?
- Lymphosarcoma eg in cats
what are the clinical signs of neoplasia of the kidney?
what is the treatment?
Clinical signs
* Haematuria, dysuria, stranguria, and pollakiuria are the most common signs
* Animals with ureteral obstruction and unilateral hydronephrosis may show signs of abdominal pain and have a palpable, enlarged kidney
* Signs of uraemia may be apparent in animals with bilateral ureteral obstruction and hydronephrosis or with urethral obstruction
* The bladder wall may be thickened, and a cord-like urethra or urethral mass(es) may be palpable rectally
Treatment:
* Treatment of majority of renal neoplasms except lymphosarcoma involves surgical removal
* Unilateral nephrectomy is usually required
- Lymphosarcoma is best managed by combination chemotherapy
- Chemotherapy is generally ineffective against renal tumours other than lymphosarcoma
what might the low incidence of lower urinart tract neoplasia in cats be linked to ?
- The low incidence in cats may be due to a difference in tryptophan metabolism that results in low urinary concentrations of carcinogenic tryptophan metabolites
What types of neoplasia are found in the lower urinary tract?
What is the most common type?
- In the lower urinary tract, primary neoplasms are more likely to be malignant
- Among primary malignant neoplasms of the lower urinary tract, transitional cell carcinomas are diagnosed most frequently in both species
- Squamous cell carcinomas, adenocarcinomas, fibrosarcomas, leiomyosarcomas, rhabdomyosarcomas, haemangiosarcomas, and osteosarcomas also are found
Cystic transitional cell tumours of the bladder are more common in what breed? what have they been associated with?
what are the charateristics of these?
what is the treatment?
Cystic transitional cell tumours are more common in certain breeds of dogs, particularly Scottish Terriers, have been associated with prior therapy with cyclophosphamide (eg treatment of previous cancer), and may be linked to exposure to herbicides and older-generation insecticides
- Transitional cell tumours are highly invasive and metastasise frequently, most commonly to the regional lymph nodes and lungs - difficult to treat
what are the clinical finding of lower urinary tract neoplasia?
- Ureteral and bladder neoplasms can cause chronic obstruction to urine flow with secondary hydronephrosis
- if unilateral ureteral tumour might not see signs of dysuria
- Urethral tumours are more likely to cause acute obstructive uropathy
- Intractable secondary bacterial urinary tract infections are commonly associated with neoplasms of the bladder and urethra
how are lower urinary tract neoplasias diagnosed?
- History and clinical signs are highly suggestive of lower urinary tract disease in animals with tumours of the bladder or urethra
- Urinalysis frequently reveals haematuria, and there may be evidence of secondary infection
- Neoplastic cells may be found in the sediment, particularly with transitional cell carcinomas
- A cystourethrogram, retrograde urethrogram, or ultrasonography is generally necessary to determine the location and extent of the tumour
◦ Biopsy of the tumour is required for definitive diagnosis - Drain the bladder with a catheter then place catheter against wall and apply negative suction, can aspirate cells and use these for cytology and diagnosis
- For bladder tumours in dogs, the veterinary bladder tumour antigen test or the BRAF mutation test may be helpful, although false +ve and -ve do occur - controversial test, means that there is a carcinoma somewhere, doesn’t have to be in the bladder
what is the treatment for lower urinary tract neoplasia?
Treatment
* Excision of the tumour, if possible, is the most beneficial therapy
* Transitional cell carcinomas are frequently located at the trigone of the bladder or in the urethra and may necessitate radical reconstructive surgery of the lower urinary tract - surgery is palliative and not curative and then will be put on a COX-2 drug (piroxicam)
◦ Prognosis is poor for these animals, even with surgery, because recurrence and metastasis occur rapidly
* Radiation therapy and/or chemotherapy with piroxicam, cisplatin, doxorubicin, vinblastine, chlorambucil, or mitoxantrone will generally prolong the life of affected animals
- Removing parts of the urethra is possible but can end up in the animal being incontinent
- Palliative stenting of the urethra is sometimes considered for tumours of the bladder neck and urethra - will often end up with the animal incontinent
Why are male cats prone to urethral obstruction?
Penile urethra is the narrowest point of the urethra, in cats this junction is intrapelvic, in dogs this it at the level of the os penis
what are the primary causes of urethral blockages in cats?
what are the perpetuating causes?
what are the iatrogenic causes?
- Intraluminal
◦ Plugs
◦ Uroliths
◦ Sloughed tissue - Mural or extraluminal
◦ Neoplasms
◦ Strictures
◦ Anomalies
◦ Reflex dyssynergia - combinations
- other
Perpetuating causes
* Intraluminal
◦ Sloughed tissues
◦ Inflammatory cells and clots
◦ Increased production of mucoprotein
* Mural or extraluminal
◦ Inflammatory swelling
◦ Muscular spasm
◦ Strictures
Iatrogenic causes
* Tissue damage
◦ Retrograde flushing solutions
◦ Catheter trauma
◦ Catheter-induced foreign body reaction
◦ Catheter-induced infection
* Post surgical dysfunction
how are urethral obstructions localised?
Probably best achieved by retrograde positive contrast urethrocystography
* Survey abdominal films
* Contrast studies
* Abdominal ultrasonography
Water soluble contrast agent that is non-ionic
what is the most common treatement option for cats that repeatedly block? what is involved?
What are the complications of this?
Perineal urethrostomy - bring the wide part of the urethra to the perineum, remove the penis (the underlying cause has not been fixed, but the cat won’t block anymore, can still get cystitis)
Complications of feline perineal urethrostomy:
* Haemorrhage
* Wound dehiscence
* Subcutaneous urine leakage - sloughing of the skin
* Urinary incontinence
* Urinary tract infection
* Urethral (stoma) stricture
