15th July 2024

Urology and Malignancy

Nephrolithiasis

Background

Renal stones can present to both medical and surgical teams. When the medical team finds itself looking after those with renal stones, this is often due to the patient initially presenting with sepsis or stones being found further down the line in a patient with acute kidney injury (AKI). Therefore, it is important to have some familiarity with the management of renal stones.

Clinical presentation

Pain and AKI are the commonly seen clinical presentations. Haematuria can be microscopic or macroscopic, whilst patients may also give a history of recurrent urine infections. Progressive chronic kidney disease (CKD) may also be a possible presentation in those with recurrent obstruction, infection and renal interstitial damage.

Patents may also have lifestyle factors which put them at risk of renal stones, such as fluid restriction to avoid bathroom breaks in the case of taxi drivers. Or they may have systemic disorders predisposing, such as gouty tophi.

Diagnosis & Treatment

Diagnosis is based on simple investigations such as urinalysis (microscopic haematuria, proteinuria, leucocytes and nitrites may all be present). Urine pH can vary depending on the type of stone present. Urine microscopy and culture can demonstrate crystals or concomitant infection.

In addition to routine bloods, it is important to check calcium levels, phosphate and serum urate.

CT-kidney-ureters-bladder (CT-KUB) is the single best test. It is a non-contrast scan; therefore, it is rapidly performed and avoids contrast administration. A KUB x-ray will only identify radio-opaque stones, such as calcium-containing or struvite stones, but not uric acid or cystine stones. Ultrasound can identify obstruction well and is sensitive for stones in the renal pelvis. However, it can miss ureteric stones.

Infection and obstruction are indications for urgent intervention. Non-steroidal anti-inflammatory drugs (NSAIDs) are often effective for the pain, however given the often co-existing renal dysfunction morphine can be used instead.

Treatment very much depends on the size of the stone and the extent of obstruction, as well as the co-existent infections. Those with stones smaller than 10mm may be able to expel them without any surgical intervention. However, this becomes less likely as the stone enlarges and is not an option if the patient is unwell.

Shockwave lithotripsy, percutaneous nephrolithotomy and ureteroscopy are all surgical options, although interventional radiology may also have a role to play.

Thereafter, patients are advised to drink plenty of water, avoid carbonated drinks and reduce salt intake. Thiazides and potassium citrate may also play a role in preventing recurrence.

References

• Steddon S, Ashman N, Chesser A, Cunningham J. Oxford Handbook of Nephrology and Hypertension (2ⁿᵈ ed.). Oxford (UK): Oxford University Press; 2014
• National Institute for Health Care Excellence. Renal and ureteric stones: assessment and management. London: NICE; 2019. (NICE Guideline No. 118). Available from: www.nice.org.uk/guidance/ng118

Renal, Bladder and Prostate Malignancy

Whilst a large part of the management of renal tract malignancies is surgical, there are aspects which it is important to be aware of for MRCP.

Renal malignancy

Around half of all renal cancers are incidental findings on imaging, a virtue of being asymptomatic. Renal cell carcinoma (RCC) accounts for the majority of renal malignancies. It is an adenocarcinoma arising from the tubular epithelium. There is a classical triad of pain, haematuria and a palpable mass which is seen in less than 10%. Pain occurs due to capsular stretching, whilst haematuria occurs on invasion of the collecting system. Scrotal varices on the left more than the right is also a classical sign. Clear cell renal cell carcinoma is the most common cause of primary renal tumours.

Diagnosis is often made with USS, followed by CT and/or MRI. PET can be used to detect occult metastases. Definitive diagnosis is made using CT-guided biopsy most commonly.

Radical surgery is often curative and is the aim of treatment in the majority of cases, unless widespread metastasis has occurred. Nephrectomy can be radical or partial. Immunotherapy and chemotherapy also play a role, however this is dependent on the type of tumour present.

Bladder malignancy

Bladder cancers are predominantly transitional cell cancers (TCCs) originating from the urothelium. Such cancers can, in fact, originate anywhere from the renal pelvis to the urethra. Squamous cell cancers are less common in the UK and the Western world, often occurring secondary to schistosomiasis infection.

The most common presenting complaint is painless haematuria, and around 15% of patients presenting with macroscopic haematuria will have bladder cancer. Patients may also have symptoms we often associate with prostatism, such as frequency urgency, nocturia and dysuria.

Cystoscopy is the mainstay of diagnosis, allowing visualisation of lesions and biopsy. Further imaging, such as CT or USS, can demonstrate obstruction and hydronephrosis, as well as allow staging.

The nature of TCCs means they often grow as papillary tumours, projecting into the bladder lumen initially. They are also often multifocal, around a third are synchronous at presentation. The majority are low grade at diagnosis, not invading muscle and therefore have a good prognosis.

Management is often surgical, with transurethral resection with or without intravesical immunotherapy bacille Calmette – Guérin (BCG).

Prostate malignancy

Whilst prostate cancer is perceived to be something men die with rather than of, it remains a common cause of cancer death in the UK. Most are adenocarcinomas arising from the prostatic urethral urothelium. Local invasion results in spread to the bladder, neck and ejaculatory ducts and seminal vesicles.  Patients may present with no symptoms at all but a positive prostate specific antigen (PSA), or may have symptoms of localised disease such as urinary hesitancy, frequency and urgency. Localised disease has a good prognosis, with 10-year survival >90%. Treatment options include surgery in the form of prostatectomy, brachytherapy, radiotherapy, hormone-based therapy or watchful waiting. Questions on benign prostatic hyperplasia may also fall under this category.

References

• Steddon S, Ashman N, Chesser A, Cunningham J. Oxford Handbook of Nephrology and hypertension (2ⁿᵈ ed.). Oxford (UK): Oxford University Press; 2014
• National Institute for Health Care Excellence. Bladder cancer: diagnosis and management. London: NICE; 2019. (NICE Guideline No. 2). Available from: www.nice.org.uk/guidance/ng02
• National Institute for Health Care Excellence. Suspected cancer: recognition and referral. London: NICE; 2019. (NICE Guideline No. 12). Available from: www.nice.org.uk/guidance/ng12
• National Institute for Health Care Prostate cancer: diagnosis and management. London: NICE; 2019. (NICE Guideline No. 131). Available from: www.nice.org.uk/guidance/ng131