Colon<unk>  with extensive metastases to the liver<unk>  diagnosis is performed by sampling of areas of the colon suspicious for possible tumor development, typically during colonoscopy or sigmoidoscopy, depending on the location of the lesion. It is confirmed by microscopical examination of a tissue sample. Medical imaging A<unk>  is sometimes initially discovered on CT scan. Presence of metastases is determined by a CT scan of the chest, abdomen and pelvis. Other potential imaging tests such as PET and MRI may be used in certain cases. The latter is often used for rectal lesions to determine its local stage and to facilitate preoperative planning. Histopathology Relative incidence of various histopathological types of<unk> . The vast majority of<unk> s are adenocarcinomas. Micrograph of<unk>  adenocarcinoma, showing "dirty necrosis". The histopathologic characteristics of the tumor are reported from the analysis of tissue taken from a biopsy or surgery. A pathology report contains a description of the microscopical characteristics of the tumor tissue, including both tumor cells and how the tumor invades into healthy tissues and finally if the tumor appears to be completely removed. The most common form of colon<unk>  is adenocarcinoma, constituting between 95% to 98% of all cases of<unk> . Other, rarer types include lymphoma, adenosquamous and squamous cell carcinoma. Some subtypes have been found to be more aggressive. Immunohistochemistry may be used in uncertain cases. Staging Staging of the<unk>  is based on both radiological and pathological findings. As with most other forms of<unk> , tumor staging is based on the TNM system which considers how much the initial tumor has spread and the presence of metastases in lymph nodes and more distant organs. The AJCC 8th edition was published in 2018.
Colorectal cancer
Irritable bowel syndrome
Anal cancer
Gastrointestinal cancer
Pancreatic cancer
Small intestine cancer
Colitis
Liver cancer