Lactating Adenoma of the Breast

Differential Diagnosis

Lactating Adenoma	Tubular Adenoma
Prominent lactational change	Lumenal secretion may be present, but cytoplasmic vacuoles lacking

These may represent the same lesion under different physiologic conditions

Lactating Adenoma	Focal Pregnancy-like Change
Circumscribed mass	Focal change in breast parenchyma

Lactating Adenoma	Secretory Carcinoma
Circumscribed mass of uniform round tubules	Sheet-like growth with focal infiltration
Myoepithelial cells present	No myoepithelial cells