My doctor explained that on a mammogram, breast cancer can appear in several ways. It often looks like a mass with an irregular shape, spiculated (spiky) margins, and high density (appears white). Another common sign is the presence of microcalcifications, which are tiny specks of calcium that appear as small white dots, sometimes clustered together. Architectural distortion, where the normal breast structure is pulled out of shape, is also a concern. Radiologists are trained to identify these subtle abnormalities.