A 30-year-old presents for evaluation of a right breast lump that is nontender and has been present for two weeks. She has been breastfeeding for three months. The patient undergoes standard mammography with a tangential magnified superior inferior oblique (SIO) as well as an ultrasound of both breasts. Upon a physical examination, the lesion is palpated and is mobile.


Lactating women tend to have increased parenchymal density due to the prominent ductal system and increased vascularity in the breast that is associated with breast feeding. Young women usually have heterogeneously to extremely dense breast tissue that is visualized on mammography. With the combination of these factors, mammography sensitivity may decrease. Ultrasound is frequently the mode of detection and diagnosis of a palpable lesion in this subset of patients. A fine needle aspiration under ultrasound guidance of this lesion shows cells that are consistent with a lactating adenoma. 

Lactating adenomas are primarily seen during the third trimester of pregnancy and during lactation. This type of lesion can be a mobile mass with no associated pain. On ultrasound this lesion appears to be oval and appear benign. 


Vashi R, Hooley R, Butler R, Geisel J, Philpotts L. Breast Imaging of the Pregnant and Lactating Patient: Physiologic Ganges and Common Benign Entities. 

Sabate JM, Clotet M, Torrubia S, Gomez A, Guerreo R, Las Heras P, Lerma E. Radiologic Evaluation of Breast Disorders Related to Pregancy and Lactation. 

Mammography

Ultrasound

A 30-year-old who has been breastfeeding for three months presents for evaluation of a right breast lump that is nontender and has been present for two weeks. 

Image IQ: 30-year-old, Breastfeeding, with Nontender Breast Lump