BCBG M size white sweater

This is a very nice white hundred percent cotton sweater with a zip at the neck They are two black stripes that go down the side of the sleeve and at the bottom of the sweater on either side is a cut out The length of the sweater is approximately 22 inches in the sleeve length is 21 inches From side to side seam is approximately 18 inches and the zipper at the neck is 6 1/2 inches On the back left shoulder is a very small yellow mark please see photo - not sure what it’s from or if it will come out however there is that small yellow stain on the back of the sweater