Tumours of the Bladder and Kidneys

List the major types of neoplasms of the kidney

Kidney tumours can be either benign (e.g. renal papillary adenoma) or malignant (e.g. renal cell carcinoma). In this post, I'll only be covering renal cell carcinoma because it was the only one talked about in depth in the lectures (probably because it's by far and away the most common). Clear cell renal cell carcinomas are the most common type of renal cell carcinomas.

Outline the aetiology, risk factors for development and pathogenesis of kidney neoplasms

Risk factors of renal cell carcinoma are pretty much the same as risk factors for many other illnesses: smoking, hypertension, obesity, genetic factors, and exposure to certain toxic chemicals. It is most commonly seen in men aged 50-70.

One genetic cause of renal cell carcinoma is Von Hippel-Lindau disease, which is a genetic disorder in which the VHL tumour suppressor gene on chromosome 3 is mutated. There are also sporadic forms of the disease in which one of the VHL genes has been lost (due to some kind of deletion of the short arm of chromosome 3), and then the other gene becomes mutated. Inactivation of VHL results in an increase in IGF-1, which is a growth factor that can upregulate hypoxia-inducible factors and ultimately vascular endothelial growth factor (VEGF).

List, in brief, the morphological and histological features of kidney neoplasms

Renal cell carcinoma arises from the epithelial cells of the proximal convoluted tubule. The cells look clear under the microscope and yellow macroscopically (i.e. to the naked eye), as the cells are filled with carbohydrates and lipids.

Outline the clinical presentations of kidney neoplasms

Renal cell carcinoma is usually pretty silent and is often simply picked up when patients are scanned for some other reason. Alternatively, patients might not get noticed at all until their disease has become severe. In patients who do show symptoms, the classic signs include haematuria, abdominal mass, and flank pain, though there may also be other symptoms. For instance, if the carcinoma spreads into the inferior vena cava and obstructs the left gonadal vein, it can result in scrotal varices. There may also be paraneoplastic syndromes from inappropriate secretion of hormones: hypercalcaemia from parathyroid hormone-related protein (PTHrP), erythrocytosis from EPO, hypertension from renin, and even Cushing's syndrome from ectopic ACTH.

Renal cell carcinoma is relatively resistant to traditional chemotherapy and radiotherapy, so surgery is often used as treatment. Immunomodulatory and anti-VEGF treatments may also be tried.

Provide an overview of staging of kidney neoplasms

Staging of renal cell carcinoma is generally done using the TNM system. The T stands for "tumour" and refers to a tumour that has not spread beyond the original site. The N stands for "nodes" and refers to a tumour that has spread to lymph nodes. Finally, the M stands for "metastatic" and refers to a tumour that has spread around the body.

List the major types of lower urinary tract neoplastic disease

The main types of bladder tumours are urothelial carcinoma (a.k.a. transitional cell carcinoma) and squamous cell carcinoma. Urothelial carcinoma is by far the most common in Australia, though squamous cell carcinoma is more common in areas where schistosomiasis (a parasite disease) is endemic.

Outline the aetiology, risk factors for development and pathogenesis of lower urinary tract neoplastic disease
List, in brief, the morphological and histological features of lower urinary tract neoplastic disease

Smoking and certain carcinogenic substances are the main risk factors for bladder cancers. They are most commonly seen in older men.

Urothelial carcinoma may have one of two types of precursor lesions: flat or papillary. Flat precursor lesions include urothelial carcinoma in situ, whereas papillary precursor lesions include papillary urothelial carcinoma. The flat precursors are more often seen in p53-dependent tumours, which tend to be more aggressive than p53-independent tumours, which often have papillary precursors. (p53 is a tumour suppressor gene that is important in the development of many cancers.)

Urothelial carcinoma is multifocal (meaning it can affect multiple sites) and recurrent (meaning that it comes back). There are two main theories as to why this is so: field effect theory and implantation theory. The field effect theory states that whatever caused the first cancer might have affected nearby sites, whereas the implantation theory states that cells from the first tumour could have broken off and implanted somewhere else. In reality, it could be a mixture of the two.

Treatment of urothelial carcinoma is basically a mix of surgery, radiation, and/or chemotherapy, depending on the situation.

Outline the clinical presentations of lower urinary tract neoplastic disease

Bladder cancer often presents with painless haematuria. Remember: painless haematuria is malignancy unless proven otherwise.

Provide an overview of staging of lower urinary tract neoplastic disease

Just like renal cell carcinoma, urothelial carcinoma also uses TNM staging. The T stage can be further divided up depending on where the tumour is. At the T1 stage, the tumour is in the lamina propria. T2 means that the tumour is in the muscularis propria, T3 in the perivesical fat, and T4 in adjacent organs. N refers to invasion of nodes, whereas M refers to metastasis.