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Colorectal Cancer Health Center

Colorectal Cancer Related Topics

Colorectal Cancer Health Center

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Cellular Classification and Pathology of Rectal Cancer

The World Health Organization (WHO) classification of tumors of the colon and rectum include the following:[1]

Epithelial Tumors

Recommended Related to Colorectal Cancer

Rectal Carcinoids

In general, rectal carcinoids smaller than 1 cm can be safely removed by endoscopic excision.[1] Excised specimens should be examined histologically to exclude muscularis invasion.[2,3,4,5] Tumors measuring 1 cm to 2 cm should be investigated by transanal endosonography or magnetic resonance imaging. Absence of muscularis invasion or regional metastases may justify local excision.[1] The outcome from treating a lesion between 1 cm and 2 cm is unclear. The metastatic risk is between 10% and 15%...

Read the Rectal Carcinoids article > >

Adenoma

Tubular.
Villous.
Tubulovillous.
Serrated.

Intraepithelial neoplasia (dysplasia) associated with chronic inflammatory diseases

Low-grade glandular intraepithelial neoplasia.
High-grade glandular intraepithelial neoplasia.

Carcinoma

Adenocarcinoma.
Mucinous adenocarcinoma.
Signet-ring cell carcinoma.
Small cell carcinoma.
Adenosquamous carcinoma.
Medullary carcinoma.
Undifferentiated carcinoma.

Carcinoid (well-differentiated neuroendocrine neoplasm)

Enterochromaffin (EC)-cell, serotonin-producing neoplasm.
L-cell, glucagon-like peptide and pancreatic polypeptide/peptide YY (PYY)-producing tumor.
Others.

Mixed carcinoma-adenocarcinoma

Others.

Nonepithelial Tumors

Lipoma.
Leiomyoma.
Gastrointestinal stromal tumor.
Leiomyosarcoma.
Angiosarcoma.
Kaposi sarcoma.
Melanoma.
Others.

Malignant lymphomas

Marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type.
Mantle cell lymphoma.
Diffuse large B-cell lymphoma.
Burkitt lymphoma.
Burkitt-like/atypical Burkitt lymphoma.

Adenocarcinomas account for the vast majority of rectal cancers. Other histologic types of colorectal cancer account for an estimated 2% to 5% of colorectal tumors.[2]

References:

Hamilton SR, Aaltonen LA: Pathology and Genetics of Tumours of the Digestive System. Lyon, France: International Agency for Research on Cancer, 2000.
Kang H, O'Connell JB, Leonardi MJ, et al.: Rare tumors of the colon and rectum: a national review. Int J Colorectal Dis 22 (2): 183-9, 2007.

WebMD Public Information from the National Cancer Institute

Last Updated: October 07, 2011

This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.