MelaFind is a new device that helps doctors identify melanoma skin cancers. In many places, it's being reported as the greatest breakthrough in skin cancer prevention to come along in decades. But, notes Gary Schwitzer at Health News Review, those pieces leave out the fact that MelaFind is actually fairly controversial. A lot of cancer researchers and docs are worried that it will give patients and doctors a false sense of security — a big issue considering the fact that MelaFind is only designed to identify small melanomas. It could turn up false negatives (or false positives) with non-melanoma skin cancers or melanomas that don't fall into a narrow type range.