Colorectal tumors

1. Big picture

Colorectal tumors mainly means colorectal cancer (CRC), usually adenocarcinoma arising from premalignant adenomas or serrated lesions. It is one of the most important internal medicine tumors because it is common, preventable by screening, often curable when localized, and clinically presents with anemia, bleeding, bowel habit change, or obstruction.

Core exam pattern:

Older patient + change in bowel habit / rectal bleeding / iron-deficiency anemia / weight loss → think colorectal cancer until proven otherwise.

Important clinical split:

| Tumor site | Typical presentation | | ---------------