Renal tumours Flashcards
Most common renal tumours in children
- Wilm’s tumour (nephroblastoma)
- Congenital mesoblastic nephroma
- Renal cell cancer in the renal tubule
Discuss Wilm’s tumour
The most common cause of RCC in children under 15 is Wilm’s disease (mainly affects children under 7) AKA neuroblastoma
- Thought to occur due to mutations in genes responsible for genitourinary development:
- Gene 11p13
- Wilms tumour 1 gene is a tumour suppressor gene, WT1 is located at 11p13
- Wilms tumour 2 is also involved with other Wilms tumour containing syndromes
- In most cases the formation of Wilm’s tumour is not actually associated with WT1or 2 mutations so the mechanism is poorly understood
Tumour composition in Wilm’s
- The tumours are mainly comprised of metanephric blastemal cells + partly developed structures of the nephron
- Tumours comprised of stromal, blastomal and epithelial cells = triphasic blastoma
- Presents as a unilateral painless, abdominal/ flank mass (rarely presents bilaterally - 6-10%)
- Metastatic disease occurs in <10% of patients and needs to be excluded carefully
- Long-term survival approaches 90% in localised disease
- Treatment is with nephrectomy, chemotherapy and xRT
Signs and symptoms of Wilm’s tumour
- Upper abdo/ flank mass/ swelling
- Abdo distension
- Abdo pain
- Pallor
- Haematuria
- Hypoglycaemia
- Hypertension
- Lymphadenopathy
- Varicocele
- Hepatomegaly
- Cholestasis
- Poor appetite
- Fever
Diagnosis of Wilm’s tumour
- Hx of painless, upper abdo/ flank mass
- Initial test of choice = ultrasound
- CT or MRI of the pelvis are useful to stage the tumour and plan therapy
- Definitive diagnosis is made by resection; either nephrectomy or biopsy
- Usually occurs aged 2-5
- Wilm’s tumours can occur extra-renally e.g. in the uterus
Examination:
- Mass is usually retroperitoneal
- Ballotable
- Does not move upon respiration
- Smooth, firm and non tender mass
- Patient may have abdo distention
Imaging: USS 1st line, large echogenic heterogenous unilateral intrarenal mass
Staging of Wilm’s tumour
Discuss renal cell carcinoma
- 85% of renal cancers of which 80% are clear cell
- Arise from proximal tubular epithelium
- Often aysymptomatic and are diagnosed incidentally
- Surgery curative in ~90% of cases
- Rare before the age of 40
- Highly vascular tumours
Main types of renal cell carcinoma
- Clear cell: 75%
- Papillary: 10%
- Chromophobe: 5%
Risk factors for RCC
- Smoking
- Male sex (2:1)
- Aged 55-84
- Living in a developed country
- Black/ American Indian
- Obesity
- Hypertension
- Family hx
- Hx of acquired renal cystic disease
Clinical features of RCC
- RCCs are often asymptomatic
- Haematuria, loin pain and a flank mass may be present
- 5% of patients have polycythaemia
- 30% of patients have hypertension due to renin secretion by the tumour
- 30% will have anaemia due to depression of EPO
- Left-sided varicocele may be associated with left side renal vein tumours as they obstruct drainage of the left testicular vein
Management of RCC
- Historically RCC has been treated with surgery (the malignancy is relatively resistant to chemotherapy and xRT) cure rates can be high for stage 1 tumours
- 1st line: surgery, unless the tumours are bilateral or the contralateral kidney is functioning poorly in which case partial nephrectomy may be indicated
- If metastases are present, nephrectomy is still recommended as this has been shown to cause regression in the metastatic disease
- Or/ local ablation therapy for a small renal mass <4cm or a tumour confined to the kidney with no regional or distant LN mets (stage 1 & 2)
Mainstay of treatment of RCC
Tyrosine kinase inhibitors
- Sunitinib has a 30-40% response rate
- Pazopanib is similar to sunitinib but is better tolerated
What is Von Hippel-Lindau syndrome?
Autosomal dominant disorder characterised by cysts and benign tumours in various organs - potential for malignant change
VHL proteins act as a tumour suppressors thus mutations leads to angiogenesis and neoplasia
Increased risk of tumours in the kidneys to transform into RCC
