Neoplasms of the bladder

Ninety-five per cent of primary bladder tumours originate in :he epithelium; the remainder arise from connective tissue angioma, myoma, fibroma and sarcoma) or are extra adrenal phaeochromocytomas.

Secondary tumours of the bladder are not rare and most commonly arise from a neighbouring organ, particularly the sigmoid and rectum, the prostate, the uterus or ovary, although bronchial neoplasms also may spread to bladder.

Pathology

Benign papillary tumours

Many histopathologists will not diagnose benign papillomas of the bladder, stating that most of them are merely better differentiated types of superficial bladder cancer. The papilloma consists of a single frond with a central vascular core with villi; it looks like a red sea-anemone (Figs 65.48 and 65.49). Inverted papilloma is a condition where the proliferative cells penetrate under normal mucosa so that the lesion is covered with smooth urothelium — it is benign.