Colon tumor
Small early flat carcinoma

Topic Completed: 1 August 2015

Revised: 28 June 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Small early flat carcinoma

Raul S. Gonzalez, M.D.
Page views in 2019: 192
Page views in 2020 to date: 33
Cite this page: Gonzalez R. Small early flat carcinoma. website. Accessed February 24th, 2020.
Definition / general
  • Term used primarily in Japan for low stage colorectal carcinomas with flat configuration
  • Not widely diagnosed in the USA; not officially recognized by the WHO
  • Represents 6% - 10% of colonic cancers diagnosed in Japan
  • Does occur in Western countries (Gut 2002;51:550)
Clinical features
  • May act aggressively despite small size
Prognostic factors
Case reports
  • May be curable using endoscopic mucosal resection
Gross description
  • Flat, plaque-like lesion, often with central depression
  • Malignancy typically measures 1 cm or less
Microscopic (histologic) description
  • Adenocarcinoma limited to mucosa or submucosa, by definition
  • Height is usually less than twice the height of adjacent normal mucosa
  • Architectural changes mild; cytologic features resemble high grade dysplasia
Microscopic (histologic) images

Images hosted on other servers:
Missing Image

Invasion of submucosa

Molecular / cytogenetics description
  • Loss of heterozygosity of 17p, 18p, 18q, and 22q, coupled with LOH of other loci (Ann Oncol 2006;17:43)
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