Colorectal tumours
Jump to navigation
Jump to search
Colorectal tumours are very common. They are the bread and butter of GI pathology. Non-tumour colon is dealt with in the colon article.
An introduction to gastrointestinal pathology is in the gastrointestinal pathology article. The precursor lesion of colorectal carcinoma (CRC) is, typical, an adenomatous polyp. Polyps are discussed in the intestinal polyps article.
Classification
- Colon & rectum, most common --by far-- is adenocarcinoma.[1]
Other tumours - many (incomplete list):[2]
- Mucinous carcinoma.
- Adenosquamous carcinoma.
- Signet-ring carcinoma.
- Squamous carcinoma.
- Neuroendocrine neoplasms (carcinoid tumours).
- Lipoma.
- Leiomyoma.
- Gastrointestinal stromal tumour (GIST) - dealt with in a separate article.
- Angiosarcoma.
- Lymphoma (Non-Hodgkin's lymphoma).
Grading
- "Adenocarcinoma in situ" and "high-grade dysplasia" is used interchangeably by many in the colon and rectum.
- Splitting hairs - adenocarcinoma in situ is invasion into the lamina propria, high-grade dysplasia does not have lamina propria invasion. Ergo, the difference (in my opinion) amounts to seeing a desmoplastic stroma (adenocarcinoma) or not seeing one (dysplasia).
Grading of tumours:
- Tis - in situ (intramucosal).
- T1 - into submucosa (through mucularis mucosae).
- This is different than elsewhere, e.g. in the small bowel tumour cells in the lamina propria is defined as T1. The rationale for the T1 definition in CRC is that no lymphatics are present in the mucosa, ergo no risk of distant spread.
- T2 - into muscularis propria.
- T3 - into fat beyond musclaris propria.
- T4 - into something else.
Nodes:
- N0 - no positive nodes.
- N1 - 1-3 positive nodes.
- N2 - 4+ positive nodes.
Staging of colorectal cancer
Simple version
Tumour/node grade for stage:[3]
- Stage I - T1 or T2 N0 M0.
- Stage II - T3 or T4 N0 M0.
- Stage III - Tx N1 or N2 M0.
- Stage IV - Tx Nx M1.
Complex version
Detailed tumour/node grade for stage:[4]
- Stage I - T1 or T2.
- Stage IIA - T3.
- Stage IIB - T4.
- Stage IIIA - T1 N1 or T2 N1.
- Stage IIIB - T3 N1 or T4 N1.
- Stage IIIC - Tx N2.
- Stage IV - Tx Nx M1.
See also
References
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 864. ISBN 0-7216-0187-1.
- ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 198. ISBN 978-0781765275.
- ↑ TN 2006 GS27.
- ↑ http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_colon_and_rectum_cancer_staged.asp