Lactating adenoma may present during or shortly after pregnancy, and it is the most common breast lesion during pregnancy and the post-partum period. Lesions may wax and wane in size with breastfeeding.
The mass is well circumscribed, composed of actively secreting, closely packed glands. Vacuolation can be prominent. Necrosis/infarction may be seen due to its rapid growth.
It is thought that these entities may simply represent a collection of hyperplastic lobules, rather than being a true adenoma.
Image Contributors
Yoon, J., Mullen, B.
Cite
Yoon, J., Mullen, B. Breast, Lactating adenoma. Digital Laboratory Medicine Library, Dept of Laboratory Medicine & Pathobiology, University of Toronto. Published
. Accessed December 17, 2025. https://dev.dlml.cflabs.ca/image/breast-lactating-adenoma-lmp72893