Special Breast Cancer Subtypes

Special types (each with better prognosis if pure): tubular carcinoma (well-formed tubules, almost always ER+, excellent prognosis), mucinous/colloid (tumour cells floating in pools of extracellular mucin), medullary-like (paradoxically high grade with pushing margins and brisk lymphocytic infiltrate, often triple-negative/BRCA1-associated, but relatively good prognosis), micropapillary (aggressive, high rate of lymphovascular invasion), metaplastic (squamous or mesenchymal differentiation, usually triple-negative, poor prognosis).