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Familial colorectal cancer Type X

Disease definition

A rare, hereditary nonpolyposis colon cancer defined in individuals meeting the Amsterdam criteria for Lynch syndrome, but lacking germline mutations in the mismatch repair genes. It is characterized by a later onset, preferential involvement of distal colon and rectum, lower risk of developing extracolonic cancer, a higher adenoma/carcinoma ratio, a higher differentiation of tumor cells, a more heterogeneous tumor architecture and an infiltrative growth pattern, when compared to Lynch syndrome cases.


Classification level: Disorder
  • Synonym(s):
    • FCCTX
  • Prevalence: -
  • Inheritance: Autosomal dominant 
  • Age of onset: -
  • ICD-10: C18.0  C18.1  C18.2  C18.3  C18.4  C18.5  C18.6  C18.7
  • OMIM: -
  • UMLS: -
  • MeSH: -
  • GARD: -
  • MedDRA: -
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