Table of Contents
Definition / general | Clinical features | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Electron microscopy description | Differential diagnosis | Additional referencesCite this page: Lobular carcinoma - signet ring variant. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastmalignantlobularsignet.html. Accessed July 14th, 2017.
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 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 features)
Case reports
- 50 year old woman with abnormal cervicovaginal pap smear (Acta Cytol 2000;44:824)
- 57 year old woman with tumor associated with papilloma (Cases J 2009;2:130)
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
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Images hosted on other servers:
Positive stains
- Mucin+ intracytoplasmic vacuoles (MUC1, 100%), CK7 (95%)
- ER (91%), PR (91%)
- GCDFP-15
- E-cadherin (29%) (Am J Clin Pathol 2004;121:884)
Electron microscopy description
- Large membrane bound vacuoles
Differential diagnosis
- GI metastasis (World J Gastroenterol 2006;12:2958)
- Signet ring cells can also be a component of ductal or mucinous / colloid carcinomas (Am J Clin Pathol 1980;73:31)
Additional references
















