Table 2

Tubular carcinoma	Sclerosing adenosis	Microglandular adenosis	Radial scar
Infiltrative, often stellate architecture	Lobulocentric architecture	Infiltrative, disorderly architecture	Complex, stellate architecture
Desmoplastic stroma Central elastosis frequent	Often central cellularity with sclerotic periphery	Fibrotic stroma	Variable stromal cellularity
Well formed, angulated tubules	Distorted, compressed tubules Frequent obliterated lumina	Uniform, round tubules	Distorted tubules
Abundant eosinophilic cytoplasm, often with apical snouts	Infrequent apical snouts	Clear, vacuolated or granular epithelial cytoplasm. No apical snouts	No apical snouts
Absent myoepithelial cells	Prominent admixed myoepithelial cells	Occasional myoepithelial cells described	Myoepithelial cells seen
Patchy, incomplete basement membrane	Uniform basement membrane	Prominent basement membrane	Basement membrane seen
Intraluminal secretion or microcalcification may be seen	Intraluminal microcalcification may be seen	Intraluminal colloid-like material which may be calcified	Intraluminal secretion uncommon. Microcalcification may be seen
Frequent associated low grade cribriform or micropapillary DCIS	May be associated apocrine metaplasia. Associated DCIS or lobular neoplasia are rare but described	Atypical features rarely described (see text)	Associated cysts, sclerosing adenosis, epithelial hyperplasia and rarely in situ or invasive carcinoma