Bilateral Galactocele

Clinical History

28-year-old lactating woman with palpable painless lumps in both breasts. History of breast augmentation surgery in 2012.

Imaging Findings

Ultrasound: In the periareolar region of the right breast; two oval heterogeneous nodules with cystic areas, non-circumscribed margins, parallel orientation.
On the contralateral breast, a hyperechoic oval nodule. None of them demonstrate posterior shadowing. Doppler study shows increased blood flow in both lesions. Both implants were intact.
Automated Breast Volume Scanner Ultrasound of the left breast, on the coronal plane a lobulated mass with circumscribed margins is seen in the periareolar region, corresponding to the palpable lump.
Neither mammography nor biopsy was needed, because the images and the history of the patient were reliable enough to make the diagnosis of galactocele.

Discussion

Galactocele is as a benign cystic lesion lined by cuboidal epithelium that contains milk. [1], often accompanied by inflammatory or necrotic debris. [2] It is the most common benign breast lesion found in women while lactating or during puerperium, although it has also been described in infants. The cysts form as a result of ductal obstruction most likely due to inflammation or in rare cases, a tumour. [3] The typical presentation is a painless palpable, smooth, mobile mass, not adhered to deep planes and it can affect one or both breasts. The radiologic appearance depends on the biochemical composition of the galactocele, that is the proportion of fat and protein, and the density and viscocity of the milk. On mammography three distinct appearances have been described. [4] When the fat percentage is higher, mass appears radiolucent (pseudolipoma). When milk is in a fresh liquid state and contains fat and water, a fat fluid level can be seen in OML incidence, the upper level containing fat and the lower level containing fluid. A mixed density mass (pseudohamartoma) can also be seen due to higher viscosity of old milk. However, mammography is of limited benefit due to increased breast density in lactating women, making ultrasound the imaging modality of choice. Galactoceles can have a wide range of sonographic appearances depending on the content of fat and water as well, and can mimic other lesions of the breast, both benign and malignant. Kopans et al [5] reported that galactoceles typically are well-circumscribed cystic nodules that contain internal echoes, and show distal acoustic enhancement, similar to a circumscribed solid breast tumour, also a wavy line can be seen due to a fat-fluid level. A complete hyperechoic nodule, as the one we show in the left breast due to the high reflectivity of the fat droplets within the lesion [6], may be seen. If poorly defined margins are found in a heterogeneous nodule the possibility of an intracystic carcinoma should be considered. [6] The treatment of a galactocele is expectant, they tend to disappear, but if not, needle aspiration of the cyst can be an effective treatment. [7]

Differential Diagnosis List

Final Diagnosis

Bilateral galactocele

URL:	https://www.eurorad.org/case/13350
DOI:	10.1594/EURORAD/CASE.13350
ISSN:	1563-4086