Colorectal cancer is typically classified based on the type of cells from which it originates and its location within the colon or rectum. The main types of colorectal cancer include:

 

  1. Adenocarcinoma: Adenocarcinoma is the most common type of colorectal cancer, accounting for about 95% of cases. It arises from the glandular cells that line the inner surface of the colon and rectum. Adenocarcinomas can develop anywhere along the length of the colon and rectum.

  2. Carcinoid tumors: Carcinoid tumors are rare tumors that can develop in the digestive tract, including the colon and rectum. They originate from neuroendocrine cells and are typically slow-growing. Carcinoid tumors are usually less aggressive than adenocarcinomas.

  3. Gastrointestinal stromal tumors (GISTs): GISTs are rare tumors that can develop in the digestive tract, including the colon and rectum. They arise from specialized cells in the wall of the gastrointestinal tract called interstitial cells of Cajal (ICCs). GISTs can be found anywhere along the gastrointestinal tract and vary in their aggressiveness.

  4. Lymphoma: Lymphoma is a type of cancer that can develop in the lymphatic tissue of the colon or rectum. It is relatively rare compared to adenocarcinoma and typically affects the rectum more often than the colon.