Columnar Cell Change and Columnar Cell Hyperplasia of the Breast

Differential Diagnosis

Flat Epithelial Atypia	Columnar Cell Change / Hyperplasia
Enlarged atypical ovoid to round nuclei	Bland oval to elongate nuclei
Chromatin may be marginated	Bland chromatin
Nucleoli may be prominent	Nucleoli not prominent
Basal polarization of nuclei usually lacking	Nuclei usually basally polarized
Frequently more abundant cytoplasm	Moderate amount of cytoplasm

Low Grade Ductal Carcinoma In Situ and Atypical Ductal Hyperplasia	Columnar Cell Change / Hyperplasia
Architectural complexity manifested by a) partial or complete filling of ducts or b) arcades or micropapillary formations	Essentially a flat lesion, lacks architectural complexity
Low grade nuclear atypia present (except some cases of ADH that have architectural complexity)	Cytologically bland

Apocrine Metaplasia	Columnar Cell Change / Hyperplasia
Cuboidal with voluminous eosinophilic cytoplasm	Lacks architectural complexity
Frequent prominent nucleoli	Bland oval nuclei