There is a circle of white spots around the nipple. What is this?

This is Montessori's nodule, which is normal. Montessori tubercle is located in the peripheral part of areola and is formed by the protrusion of the opening of Montessori gland duct. Montessori gland is a large sebaceous gland that can secrete milk, representing the middle stage of sweat gland and breast. From the eighth week of pregnancy, pregnant women are affected by the increase of estrogen and progesterone, and the mammary glands and lobules proliferate and develop, making the breasts gradually increase. It was found that the breast and its surrounding skin (areola) were dark in color, and Montessori nodules appeared around the areola. After abortion, with the gradual recovery of hormone levels, Montessori nodules can disappear.