Had an intriguing thing in June. A small brown blemish on my left leg suddenly, over a couple of days, became a mole about 10mm round and 3mm high. Took a photo with a ruler at the side to show doctor if it got "worse". However, a week later it started to go flakey and within 48 hours it had disappeared totally. In fact this afternoon I looked for it and there isn't any mark at all now! Strange!