Adenocarcinoma is the most common type of colon cancer but there are many other types of colon cancer as well. Examples include sarcoma, melanoma, carcinoid, and lymphoma. This article provides an overview of each type of colon cancer.

Adenocarcinomas

Adenocarcinomas are the most common type of colon cancer and originate in glands. Adenocarcinomas account for about 90-95% of all colorectal cancers and have two subtypes, mucinous and signet ring cell. The mucinous subtype comprises about 10-15% of adenocarcinomas while the signet ring cell subtype comprises less than 0.1% of adenocarcinomas.

Carcinoids

Colorectal carcinoids are more likely to occur in the rectum than in the colon and don't usually spread to other parts of the body.

 

They account for less than one percent of all colorectal cancers.

Leiomyosarcomas

This type of colon cancer occurs in the smooth muscle of the colon. Leiomyosarcomas account for less than two percent of colorectal cancers and have a fairly high chance of metastasizing.

Lymphomas

Colorectal lymphomas are rare and are more likely to start in the rectum than in the colon. However, lymphomas that start somewhere else in the body are more likely to spread to the colon than to the rectum. Non-Hodgkins lymphoma accounts for about 0.5% of all colorectal cancers and has many forms.

Melanomas

This type of colon cancer is rare. Usually, it results from a melanoma that started somewhere else and then spread to the colon or rectum. Melanomas account for less than two percent of colorectal cancers.