Other carcinoma subtypes, not WHO classified
Signet ring cell

Topic Completed: 1 August 2012

Minor changes: 25 June 2020

Copyright: 2002-2019,, Inc.

PubMed search: Signet ring cell [title] breast

Monika Roychowdhury, M.D.
Page views in 2019: 1,725
Page views in 2020 to date: 2,511
Cite this page: Roychowdhury M. Signet ring cell. website. Accessed November 23rd, 2020.
Definition / general
Case reports
Microscopic (histologic) description
  • Mucin fills cytoplasm and displaces nucleus
  • Usually coexists with invasive ductal NOS
  • High nuclear grade; DCIS may be present, but no lobular features (by definition)
Microscopic (histologic) images

Images hosted on other servers:

Breast metastasis to stomach

Signet ring cells form a sheet

Extracellular mucin production

Cytology description
  • Look for signet ring cells if plasmacytoid cells are identified
  • Favor ductal carcinoma if hypercellular, single signet ring cells, high nuclear grade and tubule formation
  • Favor lobular carcinoma if hypocellular, single signet ring cells and mild / moderate nuclear grade (Cytopathology 2009;20:321)
Differential diagnosis
Back to top
Image 01 Image 02