Renal Tumours

Renal tumours may occur in adults or in children but the pathology is different.

• Renal tumours account for approximately 2% of all malignancies.
• Males are more likely to be affected than females with a ratio of 2:1.2.
• More than 6,600 people are diagnosed with kidney cancer each year in the UK² and there are around 3,600 deaths.³
• The peak age of incidence for renal carcinoma is 60 to 80 years old.
• Several risk factors have been identified including smoking, obesity, hypertension, long term dialysis and Von Hippel Lindau syndrome.
• Occupations associated with an increased risk include workers exposed to cadmium or asbestos and coke oven workers in the iron and steel industries.⁴
• Hereditary renal cancers tend to be multiple, bilateral and occur at an earlier age than others.⁵
• Wilms' tumour affects about 1 in 100,000 children before the age of 15. In 5 to 10% of cases it is bilateral.

Risks for renal cell carcinoma are discussed more fully in the article on the subject.

Renal tumours may be benign or malignant, primary or secondary. Primary tumours may arise from the cells of the renal parenchyma, or from the transitional cell lining of the collecting ducts. The most common primary renal tumour in adults is renal carcinoma and this tumour accounts for approximately 2% of all newly diagnosed cancers in the UK. In children, Wilm's tumour is the most common and this tumour is the most common intra-abdominal tumour in children.

Children

• Abdominal mass
• Loin pain
• Haematuria
• Hypertension, gross haematuria, and fever are observed in 5 to 30% of patients

Adults

• Haematuria
• Loin pain
• Abdominal mass
• Recurrent fever
• Hypertension
• Oedema
• Today, more than 50% of adult renal tumours are detected when using ultrasound to investigate non-specific features.⁶ The most common of these are: hypertension, cachexia, weight loss, pyrexia, neuromyopathy, amyloidosis, elevated ESR, anaemia, abnormal LFTs, hypercalcaemia and polycythaemia.⁷
• 25 to 30% of patients present with symptoms of metastatic disease.⁷

In children a mass may be found but in adults there is often no abnormality on examination. Both renal cell carcinoma and Wilms' tumour metastasise to lung and bones.

The differential diagnosis will depend upon the presentation. There are articles on abdominal mass, loin pain and gross haematuria that will discuss the various causes.

See Renal Cell Carcinoma article and Wilms' Tumour article.

Staging of adult tumours is the Robson classification:
The Robson classification is as follows:

• Stage 1 is confined to the kidney.
• Stage 2 extends to the adrenal gland or perinephric tissues.
• Stage 3a extends into the renal vein or vena cava.
• Stage 3b involves the regional nodes.
• Stage 3c involves both regional nodes and the renal vein or vena cava.
• Stage 4a tumours extend beyond the Gerota fascia.
• Stage 4b has distant metastases.

A slightly more complex TNM system is used and recommended by the European Guidelines.⁷

For Wilms' tumour:

• Stage 1 The tumour is confined to the kidney.
• Stage 2 The tumour has begun to spread beyond the kidney to nearby structures.
• Stage 3 The tumour has spread beyond the kidney, and either there are lymph node metastases or it cannot be completely removed by surgery
• Stage 4 There is metastatic spread, usually to the lungs, liver, bone or brain.
• Stage 5 Bilateral Wilms' tumour.

See also separate Renal Cell Carcinoma and Wilms' Tumour articles.

See separate Renal Cell Carcinoma and Wilms' Tumour articles - linked in "Investigations" above.

1. National Cancer Institute (USA); Childhood Renal Tumors
2. UK kidney cancer statistics, Cancer Research UK
3. UK kidney cancer mortality statistics, Cancer Research UK
4. Kidney cancer risk factors, Cancer Research UK (website)
5. Choyke PL, Glenn GM, Walther MM, et al; Hereditary renal cancers. Radiology. 2003 Jan;226(1):33-46. [abstract]
6. Vallancien G, Torres LO, Gurfinkel E, et al; Incidental detection of renal tumours by abdominal ultrasonography. Eur Urol. 1990;18(2):94-6. [abstract]
7. Guidelines on renal cell carcinoma, European Association of Urology (2007)

• Improving outcomes in urological cancers, NICE Cancer Service Guidance (2002)
• Baumgarten D; Renal Cell Carcinoma. eMedicine, December 2006.
• Paulino AC, Coppes MJ; Wilms Tumor. eMedicine. December 2006.
• Macmillan Cancer Support (Cancerbackup); Kidney cancer information.
• Macmillan Cancer Support (Cancerbackup); Wilms tumour. Information for parents.