A bladder neoplasm is a tumor which develops in the bladder. Although it is an abnormal growth, a bladder neoplasm is not always cancer. Neoplasia, or new growth, can also take the form of a benign tumor, which is not cancerous. In the bladder, benign tumors are found less often than malignant tumors. A malignant tumor usually arises from the lining of the bladder, known as the urothelium.
Benign bladder tumors are quite rare. The two main types of benign neoplasm are known as transitional cell papilloma and nephrogenic adenoma. Sometimes a benign tumor may not cause any symptoms and it could be discovered during an investigation for another condition. In other cases, patients may discover blood in their urine. There is not usually any pain associated with this.
Malignant neoplasms are relatively common. Worldwide, the most frequently occurring type of bladder cancer is known as squamous cell carcinoma. In developed countries, a type of cancer called transitional cell carcinoma is more commonly found. The symptoms associated with bladder malignancy are similar to those experienced with benign tumors. Blood is seen in the urine, but there is not any pain, as there would be with other disorders such as a urinary tract infection.
Most often, a malignant bladder neoplasm arises in a person who smokes or who has been exposed to substances in the environment such as dyes, solvents and petroleum products. In the undeveloped world, a worm infection known as schistosomiasis can cause squamous cell carcinoma. Having a tube known as a catheter inserted into the bladder for a long time can also make the development of cancer more likely, as can the presence of bladder stones.
A malignant neoplasm may be classed as low or high grade. High-grade tumors tend to spread into the bladder wall, eventually reaching the muscle layer before traveling to other parts of the body. Low-grade tumors do not usually progress in this way. Sometimes, neoplastic cells are described as carcinoma in situ. This represents the early stage of cancer, before it has begun to spread, and it may be associated with symptoms such as pain while urinating and a need to urinate more often.
The treatment of a bladder neoplasm will vary according to whether it is malignant or benign. A benign tumor is typically removed using endoscopic techniques, where a flexible instrument with surgical tools is inserted through the passage that carries urine from the bladder. Some malignant tumors are also removed this way. Others may be treated by cutting out the whole bladder, sometimes along with nearby structures. The outlook is often good for a malignant bladder neoplasm which has not yet invaded the muscle layer.