Colon
Carcinoma
Signet ring cell carcinoma
Author: Raul S. Gonzalez, M.D.
Editorial Board Member: Catherine E. Hagen, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 7 April 2021
Last staff update: 18 June 2024
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Signet ring cell carcinoma
Table of Contents
Definition / general | Essential features | Terminology | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Signet ring cell carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumorsignetring.html. Accessed December 22nd, 2024.
Definition / general
- Rare subtype of colorectal carcinoma (< 1%) officially recognized by the WHO (Ann Surg 2013;258:775)
- > 50% of the tumor must have signet ring cell morphology to be classified as signet ring cell carcinoma
Essential features
- May form a diffuse lesion rather than a discrete mass
- Usually high stage with poor prognosis (Dis Colon Rectum 2005;48:1161, Dis Colon Rectum 1999;42:1176)
- Often metastasizes to lymph nodes, peritoneal surface and ovary (less commonly to liver) (ANZ J Surg 2001;71:703)
Terminology
- Sometimes called linitis plastica but this typically refers to signet ring cell carcinoma of stomach
Epidemiology
- May affect younger patients more than classic colorectal carcinoma (Am J Gastroenterol 1996;91:2195)
- Proximal signet ring cell cancers are a distinct subpopulation with a favorable oncologic outcome, possibly due to link with microsatellite instability (Int J Colorectal Dis 2012;27:371)
Sites
- Can occur anywhere in colon, though rectum is a less common location
Etiology
- Can be seen in carcinomas that arise through the microsatellite instability pathway (Am J Surg Pathol 2003;27:1407)
Clinical features
- Presents at earlier age and higher stage than conventional colorectal carcinoma (J Gastrointest Oncol 2014;5:18)
Diagnosis
- Diagnosis usually by biopsy, although magnifying endoscopy with narrow band imaging can also be used (BMC Gastroenterol 2015;15:86)
Prognostic factors
- Poor prognostic indicators include high tumor stage, bowel obstruction, "inefficient" surgery (Int Surg 2014;99:691)
- Prognosis poor even if signet ring cell component is < 50% (PLoS One 2015;10:e0121944)
Case reports
- 30 year old woman with primary signet ring cell carcinoma mimicking segmental Crohn's colitis (Dig Liver Dis 2005;37:537)
- 59 year old man with signet ring cell carcinoma in adenoma of sigmoid colon (Arch Pathol Lab Med 1999;123:957)
- 67 year old man with primary signet ring cell carcinoma of colon at an early stage (World J Gastroenterol 2006;12:3446)
- 72 year old woman with signet ring cell carcinoma of colon with peritonitis carcinomatosa (J Gastroenterol 2002;37:550)
Clinical images
Images hosted on other servers:
Pedunculated polyp
Stenotic rectal carcinoma
Discolored lesion
Gross description
- May diffusely infiltrate colon wall, rather than forming an exophytic mass
- Can rarely arise within a polyp
Gross images
Contributed by Raul S. Gonzalez, M.D.
Large thick lesion
Cross sections of lesion
Stricturing mass
Microscopic (histologic) description
- Proliferation of signet ring cells with intracellular mucin that displaces nucleus to side
- Pools of extracellular mucin often present as well
- Diffuse tissue infiltration less common than in gastric signet ring cell carcinoma
- May rarely be in situ or confined to a polyp (J Surg Res 2010;163:250)
- No gland formation in signet ring cell component, although it may be present elsewhere in the same lesion
Microscopic (histologic) images
Contributed by Raul S. Gonzalez, M.D.
Signet ring cell carcinoma
Positive stains
- CK20, CDX2, MUC2, MUC5AC; variable MUC1 and HepPar1 (Am J Clin Pathol 2004;121:884, Appl Immunohistochem Mol Morphol 2000;8:183)
Molecular / cytogenetics description
- Slightly lower rate of KRAS mutation than conventional colorectal carcinoma (Jpn J Clin Oncol 1998;28:202)
- May show microsatellite instability (Mod Pathol 2008;21:1533)
Sample pathology report
- Ascending colon, resection:
- Signet ring cell carcinoma, poorly differentiated (see synoptic report)
Differential diagnosis
- Benign processes with signet ring cell change (most commonly pseudomembranous colitis) (Am J Surg Pathol 2003;27:1429)
- Metastatic signet ring cell carcinoma of stomach, breast or bladder:
- Different staining patterns by immunohistochemistry (Dig Liver Dis 2006;38:609)
Board review style question #1
- Colorectal carcinomas with signet ring cells may display which of the following features?
- Concurrent BRAF and KRAS mutations
- Inability to breach the basement membrane
- Loss of CDX2 by immunohistochemistry
- Microsatellite instability
Board review style answer #1
