Breast malignant
Carcinoma subtypes
Lobular carcinoma - signet ring cell variant

Topic Completed: 1 August 2012

Minor changes: 25 June 2020

Copyright: 2002-2019,, Inc.

PubMed Search: Signet ring cell variant of lobular carcinoma

Monika Roychowdhury, M.D.
Page views in 2020 to date: 33
Cite this page: Roychowdhury M. OLD signet ring cell. website. Accessed August 7th, 2020.
Definition / general
  • "Significant" number of cells with signet rings (20% in one study)
  • First described in 1976 (Cancer 1976;37:828)
  • Signet ring: a ring that can create a wax impression or seal to close an envelope or sign a document, in a secure, not easily copied way (image)
Clinical features
  • Rare
  • Signet ring cell appearance may be due to blockage in secretion because of deletion of necessary enzyme or to disruption of E-cadherin / beta-catenin complex (J Pathol 2007;212:278)
  • Associated with poor prognosis, metastases to GI tract and female genital tract (metastases may not have signet ring cell features)
Case reports
Microscopic (histologic) description
  • "Significant" number of cells with signet rings (20% in one study)
  • Cells not as bizarre as pleomorphic lobular carcinoma
  • Some lobular features
Microscopic (histologic) images

Contributed by Dr. Mark R. Wick

Images hosted on other servers:

Mixed classic and signet ring cell morphology

Courtesy of Dr. Semir Vranic

E-cadherin, courtesy of Dr. Semir Vranic

Vacuolated cytoplasm with crescentic nuclei

Associated with papilloma

Vacuolated cytoplasm with crescentic nuclei


Positive stains
Negative stains
Electron microscopy description
  • Large membrane bound vacuoles
Differential diagnosis
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