The type of a cancer tells you which type of cell it started in. There are several types of gallbladder cancer.
There is more than one type of gallbladder cancer because there are lots of different types of cells in the gallbladder. Any of these cell types could, in theory, develop into cancer.
So if the cancer started in gland cells, it is an adenocarcinoma. If it started in the skin like cells lining the gallbladder, it is a squamous cell cancer, and so on.
This is the most common type of gallbladder cancer. More than 85 out of every 100 gallbladder cancers (85%) are adenocarcinomas. The cancer starts in gland cells in the gallbladder lining. These gland cells normally produce mucus (thick fluid).
There are three types of adenocarcinomas of the gallbladder. You might hear your doctor talking about:
- non papillary adenocarcinoma
- papillary adenocarcinoma
- mucinous adenocarcinoma
Only about 6 out of every 100 gallbladder cancers (6%) are papillary adenocarcinomas. They develop in the tissues that hold the gallbladder in place (connective tissues). This type of gallbladder cancer is less likely to spread to the liver and nearby lymph nodes. It tends to have a better outlook than most other types of gallbladder cancer.
With mucinous adenocarcinomas, the cancer cells are often in pools of mucus. Only about 1 or 2 out of every 100 gallbladder cancers (1 or 2%) are mucinous adenocarcinoma.
Squamous cell cancer
Squamous cell cancers develop from the skin like cells that form the lining of the gallbladder, along with the gland cells. They are treated in the same way as adenocarcinomas.
Adenosquamous carcinomas are cancers that have both squamous cancer cells and glandular cancer cells. Your doctor might call this a mixed histology. These cancers are treated in the same way as adenocarcinomas.
Small cell cancer
Small cell carcinomas are also called oat cell carcinomas. This is because the cancer cells have a distinctive oat like shape.
Sarcoma is the name for a cancer that affects the supportive or protecting tissues of the body, also called the connective tissues. Muscles, blood vessels and nerves are all connective tissues. So a cancer that begins in the muscle layer of the gallbladder is called a sarcoma.
Neuroendocrine tumours are rare cancers that grow from hormone producing tissues, usually in the digestive system. The most common type of neuroendocrine tumour is called carcinoid.
Lymphoma and melanoma
These are extremely rare types of gallbladder cancer. They are not necessarily treated in the same way as the other types. For example, lymphomas tend to respond well to chemotherapy and radiotherapy. So it is very unlikely that you would have surgery to treat a lymphoma.