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Surgical Pathology Criteria

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Signet Ring Adenocarcinoma of the Colon and Rectum


  • Adenocarcinoma, arising in the colon or rectum, of which >50% of the lesion is composed of signet ring cells

Return to Colorectal Adenocarcinoma NOS

Diagnostic Criteria

  • Colorectal adenocarcinoma composed of >50% signet ring cells
    • Distended mucin vacuole displaces cytologically atypical nucleus to one side
  • May also be associated with extracellular mucin
  • If ≤50% signet ring cells, designate as:
    • Adenocarcinoma with signet ring component

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting/updates : 1/31/10, 11/12/11

Supplemental studies


Results for colorectal adenocarcinoma NOS
p63 Negative
CK5/6 5%
CDX2 75-98%
CK7 5-10%
CK20 95

  • CDX2 has been reported to be positive in 3/3 colorectal signet ring carcinomas

Differential Diagnosis

Carcinoma ex Goblet Cell Carcinoid, Signet Ring Cell Type Colorectal Signet Ring Adenocarcinoma
At least focal presence of typical GCC Lacks typical GCC component
No surface adenoma or in situ lesion May have surface adenoma or in situ component
Essentially always originates in appendix Arises in colorectum
Neuroendocrine stains are not useful for this differential as positive cells are usually infrequent in goblet cell carcinoid and may be seen in nonendocrine carcinomas.


  • Poor prognosis
  • Spreads preferentially to the peritoneal surface and the ovaries
    • Adenocarcinoma with signet ring component (<50%) has the same pattern of spread

Grading / Staging


  • Signet ring adenocarcinoma is graded according to MSI status
    • MSI-H carcinomas are low grade
    • MSS or MSI-L carcinomas are high grade



  • Bosman FT, Carneiro F, Hruban RH, Thiese ND (Eds). WHO Classifiication of Tumors of the Digestive System, IARC, Lyon 2010
  • Sasaki S, Masaki T, Umetani N, Futakawa N, Ando H, Muto T. Characteristics in primary signet-ring cell carcinoma of the colorectum, from clinicopathological observations. Jpn J Clin Oncol. 1998 Mar;28(3):202-6.
  • Kang H, O'Connell JB, Maggard MA, Sack J, Ko CY. A 10-year outcomes evaluation of mucinous and signet-ring cell carcinoma of the colon and rectum. Dis Colon Rectum. 2005 Jun;48(6):1161-8.
  • Pande R, Sunga A, Levea C, Wilding GE, Bshara W, Reid M, Fakih MG. Significance of signet-ring cells in patients with colorectal cancer. Dis Colon Rectum. 2008 Jan;51(1):50-5.
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