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Table of Contents
Definition / general | Positive stains | Molecular / cytogenetics description | Additional referencesCite this page: General. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastmalignantcarcinomasubtypesgeneral.html. Accessed July 14th, 2017.
Definition / general
- Histological subtypes (also called special types) other than ductal NOS account for up to 25% of invasive breast carcinomas, although lobular constitutes about 10% of invasive breast carcinoma
- Have distinctive clinical features only if “pure”; i.e. if histologic features are present in > 90% of tumor
- Histological subtypes often differ greatly in age of onset (Cancer Epidemiol Biomarkers Prev 2006;15:1899), clinical presentation and hormone receptor profiles (Br J Cancer 2005;93:1046), prognosis (Int J Cancer 2007;121:127, Br J Cancer 2004;91:1263), and response to therapy (Breast Cancer 2009;16:168)
- Subtypes can often be suspected / diagnosed by fine needle aspiration (Diagn Cytopathol 2007;35:408)
- Subtypes should be assigned a histologic grade
Positive stains
- Breast carcinomas are usually CK7+, CK20–, except mucinous / colloid (often CK20+) and < 5% of special types (Ann Diagn Pathol 1999;3:350)
Molecular / cytogenetics description
- DNA microarray profiling studies have divided invasive breast carcinoma into molecular subtypes: luminal A (ER+, HER2–), luminal B (ER+, HER2+), HER2 positive (ER–, HER2+), normal breast-like (ER+, PR+, HER2–) and basal-like (ER–, HER2–, EGFR+ or cytokeratin 5 / 6+)
- Most histologic subtypes other than lobular and apocrine belong to only one molecular subtype (J Pathol 2008;216:141)
- By hierarchical clustering analysis, some histological subtypes types appear to be discrete entities (micropapillary carcinoma), but others appear similar to each other (tubular and lobular)
Additional references
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