Signet ring cell carcinoma

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.

Signet ring cell carcinoma
Diagnosis in short
Signet ring cell carcinoma. H&E stain
LM	ovoid cells with abundant cytoplasm and a peripheral crescentic hyperchromatic nucleus
LM DDx	serous fat atrophy, benign histiocytes (mucocele, xanthoma)
Stains	PAS stain
IHC	pankeratin +ve, CD68 -ve
Site	stomach, small intestine, large intestine, breast, pancreas, urinary bladder, prostate gland, lung
Associated Dx	Invasive lobular carcinoma, mucinous carcinoma
Syndromes	familial diffuse gastric cancer
Prevalence	uncommon
Endoscopy	linitis plastica (classic finding in the stomach)
Prognosis	poor

Signet ring cell carcinoma
External resources
EHVSC	9982
Wikipedia	Signet ring cell carcinoma

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:

• Esophagus.
  • >50% signet ring cells - as per a study definition.
• Stomach.
• Small intestine
• Large intestine.
• Breast
• Pancreas.
• Urinary bladder.
• 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.
• Mucocele - muciphages may mimic signet ring cells.
  • Muciphages = cytoplasm lightly eosinophilic, multivaculated (classic) or finely reticulated.
• Gastric xanthoma.
• Goblet cell adenocarcinoma (crypt cell carcinoma or goblet cell carcinoid).
• Ischemic mucosal changes - cells within the lumen.

Images

• 

  A medieval signet ring. On the left it is lying flat and looks similar to a so called signet ring cell. (WC/Staves)

www

• Signet rings (engravingarts.com).

Case - stomach

• 

  SRCC - low mag. - demonstrating that it can be subtle. (WC/Nephron)

• 

  SRCC - high mag. (WC/Nephron)

• 

  SRCC - very high mag. (WC/Nephron)

Case - bladder

• 

  SRCC - bladder - intermed. mag.

• 

  SRCC - bladder - intermed. mag.

• 

  SRCC - bladder - high mag.

• 

  SRCC - bladder - very high mag.

Additional cases

• 

  SRCC metastasis. (WC/Nephron)

• 

  SRCC. (WC/KGH)

• 

  SRCC - PAS stain. (WC/KGH)

Stains

• Alcian blue-PAS stain +ve (stomach and colorectum).
• PAS stain +ve.
• Mucicarmine stain -ve (stomach).^{[citation needed]}

Note:

• Mucin staining varies somewhat by the anatomical site.

IHC

• AE1/AE3 +ve.
• CK7 +ve (usually).

See also

• Cancer.
• Starvation.