NEOPLASMS OF THE BLADDER

NEOPLASMS OF THE BLADDER

primary bladder tumours: 95% originate in transitional epithelium; the remainder arise from connective tissue (angioma, myoma, fibroma and sarcoma) or are extra-adrenal phaeochromocytomas.
Secondary tumours: most frequently arise from the sigmoid and rectum, the prostate, the uterus or the ovaries, although bronchial neoplasms may also spread to the bladder.
Pathology
Benign papillary tumours
The papilloma consists of a single frond with a central vascular
core with villi; it looks like a red sea anemone. It is benign.
CARCINOMA OF THE BLADDER
Histological types of bladder cancer include
1-Transitional cell carcinoma.Over 90% are urothelial in origin.
2-Pure squamous carcinoma is uncommon (approximately 5%), except in areas where bilharzia is endemic.
3-Primary adenocarcinoma,which arises either from the urachal remnant or from areas of glandular metaplasia,(1–2% of cases).
Urothelial cell carcinoma(TCC)
Aetiology
Cigarette smoking is the main aetiological factor (40% of cancers).
Occupational exposure to urothelial carcinogens remains common.
The first suspicion of a chemical cause for workers in aniline dye factories. Subsequent investigation demonstrated that other compounds may be carcinogenic: 2-naphthylamine; 4-aminobiphenyl; benzidine; chlornaphazine;..etc.
Occupations associated with an increased risk of bladder cancer are: dye workers; tyre rubber and cable workers; petrol workers; leather workers; shoe manufacturers and cleaners; painters; hairdressers; lorry drivers; chemical workers; ..etc
Balkan nephropathy is associated with an increased incidence of upper tract urothelial tumours .
A series of genetic events has been clearly implicated in cancer
formation .Activation of dominantly acting oncogenes such as ras and c-erbB-1 and -2,and transcription factors such as E2F3, have been reported in bladder cancer, as has the inactivation of tumour-suppressor genes such as p53, p21, p16 and the retinoblastoma gene. Activation of many other genes occurs including those coding for enzymes that dissolve the basement membrane, such as the metalloproteinases (stromelysin, collagenases and elastase), lysosomal enzymes such as the cathepsins and others including urinary plasminogen activators; angiogenic factors [e.g. vascular endothelial growth factor (VEGF)] and other peptide growth factors such as the epidermal growth factor and its receptor also have a role to play. These changes are common to several tumour types, including prostate cancer.