Not only can melanoma grow inside the belly button, but this particular location makes the cancer potentially more aggressive and able to spread faster than if it were, for example, located on the chest, back or leg.

“Melanoma can develop on any skin surface, even the belly button,” says Erum Ilyas, MD, a board certified dermatologist who performs adult and pediatric medical dermatology, cosmetic dermatology and skin cancer treatment at Montgomery Dermatology, LLC.

How common is a belly button melanoma?

“Umbilical or belly button tumors are not common,” says Dr. Ilyas.

“Cancers that metastasize to the belly button from internal cancers (gynecological, gastrointestinal, lymphoma, etc.) are actually more common than primary cancers found in the belly button.

“This type of tumor [metastatic] is called a Sister Mary Joseph nodule.  In women it is most commonly metastatic from ovarian cancer and in men from gastric carcinoma.

“That being said, melanoma in the umbilicus is rare but should be checked for because it is thought that if or when it occurs, that it may be more likely to spread or metastasize quickly because the area is highly vascular and has old connections to the internal organs.”

The Dermatology Online Journal (Mangas et al) says that belly button melanomas don’t seem to be frequent, but that the “real incidence is difficult to determine due to the lack of statistics about it on the literature.”

A report by Monta et al is chilling:

What makes navel melanomas unique is that the natural creasing of the inside of a belly button can obscure a growing cancer.

Furthermore, in overweight people it’s more difficult to get a good look.

And unfortunately, not every dermatologist says during the annual skin exam, “Okay, I’m now going to inspect your belly button.”

In order for a doctor to adequately inspect it, the doctor must pry at the umbilicus in different directions to spread apart its natural folds that might be concealing a suspicious lesion. Simply hovering over it with a dermatoscope isn’t enough.

Melanoma in Belly Button Found by Accident

A report in Aesthetic Plastic Surgery (April 2013) cites the case of a woman who was under general anesthesia for a planned harvesting of fat from her abdominal area for breast asymmetry contouring.

Entryway for the fat is done through the navel so that the scar can be concealed.

Before cutting, the surgeons noticed a pigmented lesion inside the belly button which had gone unnoticed during the preop exam.

The spot turned out to be a melanoma in situ that had arisen from a pre-existing mole.

Dr. Ilyas is the founder of the AmberNoon line of fashionable sun-protective clothing. 
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  
Sources
bmcresnotes.biomedcentral.com/articles/10.1186/s13104-015-1096-x
escholarship.org/uc/item/2nm0d006
search.proquest.com/openview/0111df8b07d79c3f2865c2342c8d0bce/1?pq-origsite=gscholar&cbl=54048 melanoma inside belly button