Ms. Oppel is a medical assistant in Manhattan in the office of Dr. Doris Day, one of the first dermatologists to buy the machine. Developed by Mela Sciences of Irvington, N.Y., the system uses pattern-recognition algorithms to help a dermatologist who has picked out a suspicious pigmented spot to decide whether to perform a biopsy. The device may find an audience among sun-seekers worried about developing an aggressive skin cancer: the National Cancer Institute estimates that about 9,500 Americans this year will die of melanoma of the skin.
Yet the device is polarizing the field of skin-cancer detection.
For decades, dermatologists have used their eyes, along with a magnifier called a dermatoscope, to try to distinguish abnormal but benign lesions from potential melanoma in order to avoid unneeded biopsies. Some dermatologists argue that these low-tech tools are still the most useful and worry that their colleagues are falling for expensive, cool-looking gadgets that may simply offer extraneous, and perhaps incorrect, data.
"This technology should still be considered to be in the developmental stage," said Dr. Roberta Lucas, an instructor of clinical dermatology at the Northwestern University Feinberg School of Medicine in Chicago. "We are better off when the system supports doctors who are thorough and unhurried; who examine and listen carefully and who empower patients to practice good surveillance and sun protection."
In fact, some members of an expert medical panel asked to review MelaFind a few years ago for the Food and Drug Administration warned that the device had the potential to give doctors and patients a false sense of security. While MelaFind can analyze small pigmented spots identified by dermatologists as having signs of melanoma, it is not designed to evaluate other problems: large melanomas, colorless melanomas or two other types of skin cancer — basal and squamous cell carcinoma.
Dr. Amy E. Newburger, a dermatologist in Scarsdale, N.Y., who was a member of that F.D.A. panel, told me that she was concerned that a doctor could inadvertently use MelaFind on a non-melanoma skin cancer, receive a score indicating that the spot was not irregular, and erroneously decide not to biopsy it. She voted against recommending the device for F.D.A. approval.
Some biostatisticians are also critical of MelaFind, saying the device can recognize a high percentage of melanomas correctly because it also falsely scores as positive so many non-melanomas — potentially prompting doctors to perform unnecessary biopsies.
To help me visualize that issue, Jason Connor, a biostatistician at Berry Consultants, a biostatistics consulting firm, compared the accuracy of MelaFind in distinguishing non-melanomas to a hypothetical pregnancy test which, used on 100 nonpregnant women, would mistakenly conclude that 90 of them were pregnant.
"My concern with MelaFind is that it just says everything is positive," Mr. Connor said. A member of the F.D.A. panel, he abstained on a vote about whether the device's intended uses outweighed the risks.
"I don't think this helps an aggressive doctor," Mr. Connor told me, "and unaggressive doctors could do just as well if they were more diligent without the device."
To develop MelaFind's current algorithm, researchers trained the system on digital images of more than 10,000 pigmented lesions, programming it to recognize irregularities like asymmetry, color variability and cellular disorganization characteristic of melanomas. Company executives said Mela Sciences deliberately calibrated the machine to catch as many melanomas as possible, understanding that such a high setting could lead doctors to biopsy normal tissue.
"It will err on the side of caution," said Claudia Beqaj, director of commercialization at Mela Sciences. "We wanted to set the system to have such a high sensitivity that we didn't miss any melanomas."
(In a company-financed study submitted to the F.D.A., the device missed two out of 127 evaluable melanomas. One F.D.A. reviewer concluded: "There is inadequate data to determine any true value added for MelaFind for use by a dermatologist or other provider.")
Ms. Beqaj emphasized that MelaFind was intended as a supplementary test that provided extra information about a mole, not as a substitute for a dermatologist's own expertise.
"If they blindly followed MelaFind, they would be biopsying more," Ms. Beqaj said. "The doctor has to make their own clinical judgment."
Dr. Day finds the system quite informative. Last week, she gave me a demonstration in her office on the Upper East Side of Manhattan.
Dr. Day picked out what she called an "ugly duckling" mole on the left arm of Ms. Oppel, who had kindly agreed to play the role of patient. Another medical assistant removed a hand-held scanner from the MelaFind console and pressed it against the mole.
The device uses 10 different wavelengths of light to see up to 2.5 millimeters deep into the skin and capture images of its different layers. Within a minute, the machine displayed a numerical score, indicating that Ms. Oppel's mole was irregular, but not highly likely to be a melanoma. Since the images on the screen indicated that the darkest part of the mole was concentrated around a hair follicle, an expected pigmentation pattern, Dr. Day concluded there was no immediate need for a biopsy.
"It helps me see what I cannot see with my eye," Dr. Day said. "I have great comfort that I am not missing a melanoma."
(Dr. Day has been a paid device investigator and speaker for Mela Sciences; she appears inpromotional videos on the MelaFind Web site).
In late 2011, the F.D.A. approved MelaFind for sale in the United States. But, given the concerns that general physicians not trained as skin experts might miss a skin cancer, the agency restricted the use of the device to dermatologists — and then only after the doctors had successfully completed a MelaFind training program. So far, Ms. Beqaj says, the company had sold about 150 of the devices, which cost about $10,000, in the United States and Germany.
Since health insurance does not currently cover the service, patients are paying $25 to $175 for the first mole evaluation and around $25 for subsequent moles, doctors say.
WHETHER or not MelaFind eventually gains traction among dermatologists, the device is nevertheless significant, said Dr. Hensin Tsao, the director of the melanoma and pigmented lesion center at Massachusetts General Hospital in Boston, because it introduces the idea of artificial intelligence in dermatology.
Unlike an X-ray or mammography device that requires a medical professional to read the images and identify abnormalities, Dr. Tsao said, MelaFind both captures images and analyzes the likelihood of melanoma. That extra intelligence, its accuracy notwithstanding, is bound to change doctors' interactions with patients.
Dr. Tsao's clinic is participating in a post-marketing study of MelaFind, financed by Mela Sciences. And he said he and his colleagues were thinking hard about how to develop a role for such new devices in informing physicians and patients.
"Until now, you trusted the doctor to make the decision," Dr. Tsao said. "Now you've got a three-way interaction. It's a brand new paradigm."
