Oil cysts
Breast oil cysts are fluid-filled sacs that appear smooth and squishy. They can be observed by self-examinations and imaging tests (mammogram or breast MRI).
Oil cysts commonly occur after breast surgery due to the breakdown of fatty tissue. They are called oil cysts because they are body fats that have a liquid form. They cannot turn cancerous and do not increase the chance of having breast cancer, but they may happen in association with underlying cancer. They can be left untreated or aspirated with a fine needle to remove the cyst.
Mastitis
This is an infection of the breast and is characterized by redness, swelling, and pain. In some cases, it is difficult to differentiate between mastitis and inflammatory breast cancer, which usually starts with redness, tenderness, and a rash, instead of a lump.
Duct Ectasia
Mammary duct ectasia is a harmless condition that occurs when the milk ducts are blocked and swollen, leading to grayish release. In some cases, it causes a little lump beneath the nipple or makes the nipple move inwards. It occurs mostly around the age of menopause [5].