What type of breast lesion is commonly seen after trauma or radiation therapy?

Fat necrosis is commonly seen after trauma or radiation therapy due to the disruption of adipose tissue in the breast. When there is an injury, such as a contusion or surgical trauma, fat cells can become damaged, leading to an inflammatory response. This process can also occur following radiation therapy, which can affect nearby fatty tissue.

In cases of fat necrosis, patients may present with palpable masses or changes seen on imaging studies such as mammograms. The appearance of these lesions can vary, often mimicking malignancies, which is why careful interpretation and sometimes follow-up imaging or biopsy are necessary.

The other types of lesions mentioned do not typically present in the context of trauma or radiation therapy. A galactocele is a cystic lesion associated with milk accumulation, often occurring during lactation. Invasive carcinoma is a malignancy that arises independently of trauma or radiation contexts. A benign fibroadenoma is a common tumor in young women not typically related to trauma or radiation. Therefore, fat necrosis is specifically recognized for its association with trauma and radiation effects on breast tissue.