Nipples and areola (the pigmented area around the nipple) come in a range of shapes, colours and sizes, and there may be significant asymmetry between the two sides.
Sometimes, they are not proportionate to the rest of the breast. To make them more cosmetically appealing, they may need surgical reshaping. At times, it may even be necessary to reconstruct the whole nipple-areola complex from scratch when they have been removed due to breast cancer.