You know that melanoma can indeed grow “in a nail” and cause a dark streak, but can this band of cancer ever be green?

Or how about mostly brown or black with a little bit of green in it?

Melanoma doesn’t actually grow IN a nail. It grows on the tissue beneath the nail: the nail matrix.

When the tumor gets big enough, it will be visible through the nail. The nail itself is actually dead and cannot support growth of anything.

The matrix (nail bed) is alive and can be the site of melanoma, though this is a rare form of the disease. This cancer is prolific at spreading to the lungs, liver and brain if not caught in time.

It can occur in both fingernails and toenails and usually presents as a brown to black streak, band or line that runs the length of the nail. Sometimes the discoloration looks more like a dark smudge or smear rather than of a linear shape.

Melanoma in a Nail Appearing Green?

“Green discoloration under a nail is usually a symptom of a bacterial infection called Pseudomonas,” says Allison Arthur, MD, FAAD, board certified dermatologist with Sand Lake Dermatology Center in
Orlando, FL.

“This can develop in people whose nails have prolonged exposure to water or have had a traumatic nail injury,” continues Dr. Arthur.

“Dermatologists refer to this condition as ‘green nail syndrome.’

“I have never seen a melanoma cause green discoloration in a nail, but if your dermatologist has any suspicion for melanoma when they examine the area, a biopsy must be done.”

dr. arthur

Dr. Arthur is a Mayo Clinic-trained dermatologist and dermopathologist who cares for patients of all ages, providing skin cancer and other medical/surgical treatments, plus cosmetic treatments.