View source for Signet ring cell carcinoma

{{ Infobox diagnosis
| Name       = {{PAGENAME}}
| Image      = Signet ring cell carcinoma - very high mag.jpg 
| Width      =
| Caption    = Signet ring cell carcinoma. [[H&E stain]]
| Micro      = ovoid cells with abundant cytoplasm and a peripheral crescentic hyperchromatic nucleus 
| Subtypes   =
| LMDDx      = [[serous fat atrophy]], benign histiocytes ([[mucocele]], [[gastric xanthoma|xanthoma]])
| Stains     = [[PAS stain]]
| IHC        = pankeratin +ve, CD68 -ve
| EM         =
| Molecular  =
| IF         =
| Gross      =
| Grossing   =
| Site       = [[stomach]], [[small intestine]], [[large intestine]], [[breast]], [[pancreas]], [[urinary bladder]], [[prostate gland]], [[lung]]
| Assdx      = [[Invasive lobular carcinoma]], [[mucinous carcinoma]]
| Syndromes  = [[familial diffuse gastric cancer]]
| Clinicalhx =
| Signs      =
| Symptoms   =
| Prevalence = uncommon
| Bloodwork  =
| Rads       =
| Endoscopy  = [[linitis plastica]] (classic finding in the stomach)
| Prognosis  = poor
| Other      =
| ClinDDx    =
}}
{{ Infobox external links
| Name           = {{PAGENAME}}
| EHVSC          = 9982
| pathprotocols  = 
| wikipedia      = Signet ring cell carcinoma
| pathoutlines   =
}}
'''Signet ring cell carcinoma''', abbreviated '''SRCC''', is a type of malignant epithelial neoplasm that can arise from a number of places. It is commonly associated with the [[stomach]].

==General==
*Signet ring cell carcinoma are notoriously easy to miss in a small biopsy.
**It has been said that there are two types of pathologists... those that have missed SRCCs ''and'' those that will miss SRCCs.
*The name comes from the shape of cells. They look like signet rings that are lying flat on the ground and one is looking from above - see microscopic section.

===Anatomical Site===
It may arise from the:<ref>URL: [http://cancerhelp.cancerresearchuk.org/about-cancer/cancer-questions/what-is-a-signet-cell-cancer http://cancerhelp.cancerresearchuk.org/about-cancer/cancer-questions/what-is-a-signet-cell-cancer]. Accessed on: 7 March 2012.</ref>
*[[Esophagus]].
**>50% signet ring cells - as per a study definition.<ref>URL: [https://clinicaltrials.gov/ct2/show/NCT01824966 https://clinicaltrials.gov/ct2/show/NCT01824966]. Accessed on: April 23, 2022.</ref>
*[[Stomach]].
*[[Small intestine]]
*[[Large intestine]].
*[[Breast]]
*[[Pancreas]].
*[[Urinary bladder]].
*[[Prostatic_signet_ring_cell_carcinoma|Prostate gland]]. 
*[[Lung]].

==Microscopic==
Features:
*Signet ring cells resemble signet rings.
**They contain a large amount of mucin, which pushes the nucleus to the cell periphery. 
**The pool of mucin in a signet ring cell mimics the appearance of the finger hole.
**The nucleus mimics the appearance of the face of the ring in profile.
*Signet ring cells are typically 2-3x the size of a lymphocyte.
**Smaller than the typical adipocyte.
*Often have a crescent-shaped ''or'' ovoid nucleus.
**Capillaries sectioned on their lumen have endothelial cells - the nuclei of these are more spindled.

Note:
*SRCs are usually close to friend, i.e. they are adjacent to another SRC.
**This helps differentiate SRCs from capillaries sectioned on their lumen.
*The mucin is often clear on H&E... but maybe eosinophilic.

DDx:
*[[Serous fat atrophy]].<ref name=pmid6222282>{{Cite journal  | last1 = Clarke | first1 = BE. | last2 = Brown | first2 = DJ. | last3 = Xipell | first3 = JM. | title = Gelatinous transformation of the bone marrow. | journal = Pathology | volume = 15 | issue = 1 | pages = 85-8 | month = Jan | year = 1983 | doi =  | PMID = 6222282 }}</ref>
*[[Mucocele]] - muciphages may mimic signet ring cells.<ref name=pmid9591723>{{Cite journal  | last1 = De Petris | first1 = G. | last2 = Lev | first2 = R. | last3 = Siew | first3 = S. | title = Peritumoral and nodal muciphages. | journal = Am J Surg Pathol | volume = 22 | issue = 5 | pages = 545-9 | month = May | year = 1998 | doi =  | PMID = 9591723 }}</ref>
**Muciphages = cytoplasm lightly eosinophilic, multivaculated (classic) or finely reticulated.
*[[Gastric xanthoma]].
*[[Crypt cell carcinoma]] (goblet cell carcinoid).<ref name=pmid22933998>{{Cite journal  | last1 = Pericleous | first1 = M. | last2 = Lumgair | first2 = H. | last3 = Baneke | first3 = A. | last4 = Morgan-Rowe | first4 = L. | last5 = E Caplin | first5 = M. | last6 = Luong | first6 = TV. | last7 = Thirlwell | first7 = C. | last8 = Gillmore | first8 = R. | last9 = Toumpanakis | first9 = C. | title = Appendiceal goblet cell carcinoid tumour: a case of unexpected lung metastasis. | journal = Case Rep Oncol | volume = 5 | issue = 2 | pages = 332-8 | month = May | year = 2012 | doi = 000339607 | PMID = 22933998 }}</ref>
*Ischemic mucosal changes - cells within the lumen.<ref name=pmid22082777>{{Cite journal  | last1 = Dhingra | first1 = S. | last2 = Wang | first2 = H. | title = Nonneoplastic signet-ring cell change in gastrointestinal and biliary tracts: a pitfall for overdiagnosis. | journal = Ann Diagn Pathol | volume = 15 | issue = 6 | pages = 490-6 | month = Dec | year = 2011 | doi = 10.1016/j.anndiagpath.2011.07.006 | PMID = 22082777 }}</ref> 

===Images===
<gallery>
Image:Medieval Signet Ring (FindID 226489).jpg|A medieval signet ring. On the left it is lying flat and looks similar to a so called signet ring cell. (WC/Staves)
</gallery>
====www====
*[http://www.engravingarts.com/sales/LVX2.jpg Signet rings (engravingarts.com)]. 
====Case - stomach====
<gallery>
Image:Signet_ring_cell_carcinoma_-_low_mag.jpg | SRCC - low mag. - demonstrating that it can be subtle. (WC/Nephron)
Image:Signet_ring_cell_carcinoma_-_high_mag.jpg | SRCC - high mag. (WC/Nephron)
Image:Signet_ring_cell_carcinoma_-_very_high_mag.jpg | SRCC - very high mag. (WC/Nephron)
</gallery>
====Case - bladder====
<gallery>
Image: Signet ring cell carcinoma of the urinary bladder -- intermed mag.jpg | SRCC - bladder - intermed. mag.
Image: Signet ring cell carcinoma of the urinary bladder - alt -- intermed mag.jpg | SRCC - bladder - intermed. mag.
Image: Signet ring cell carcinoma of the urinary bladder -- high mag.jpg | SRCC - bladder - high mag.
Image: Signet ring cell carcinoma of the urinary bladder -- very high mag.jpg | SRCC - bladder - very high mag.
</gallery>

====Additional cases====
<gallery>
Image:Signet_ring_cells_5.jpg | SRCC metastasis. (WC/Nephron)
Image:Gastric_signet_ring_cell_carcinoma_histopatholgy_(1).jpg | SRCC. (WC/KGH)
Image:Gastric_signet_ring_cell_carcinoma_histopatholgy_(2)_PAS_stain.jpg | SRCC - PAS stain. (WC/KGH)
</gallery>

==Stains==
*Alcian blue-PAS stain +ve (stomach and colorectum).<ref name=pmid23573317>{{Cite journal  | last1 = Terada | first1 = T. | title = An immunohistochemical study of primary signet-ring cell carcinoma of the stomach and colorectum: I. Cytokeratin profile in 42 cases. | journal = Int J Clin Exp Pathol | volume = 6 | issue = 4 | pages = 703-10 | month =  | year = 2013 | doi =  | PMID = 23573317 }}</ref>
*PAS stain +ve.
*[[Mucicarmine stain]] -ve (stomach).{{fact}}

Note:
*Mucin staining varies somewhat by the anatomical site.<ref name=pmid16740030>{{cite journal |authors=Nguyen MD, Plasil B, Wen P, Frankel WL |title=Mucin profiles in signet-ring cell carcinoma |journal=Arch Pathol Lab Med |volume=130 |issue=6 |pages=799–804 |date=June 2006 |pmid=16740030 |doi=10.5858/2006-130-799-MPISCC |url=}}</ref>

==IHC==
*AE1/AE3 +ve.
*CK7 +ve (usually).

==See also==
*[[Cancer]].
*[[Starvation]].

==References==
{{Reflist|2}}

[[Category:Gastrointestinal pathology]]
[[Category:Diagnosis]]