What Could Brown Spots On Penis Glans Suggest?

Hello In the last three or four weeks a small brown spot has developed on the glans penis. rather like a liver spot on the back of a hand. It does not seem different in texture to the surrounding skin but has grown oval in shape three millimeters or so long by two wide. There is no discomfort it seems neither to be raised or depressed skin. Should I attend a doctor about this?