For many, getting a tattoo seems fairly harmless outside of a little pain and perhaps some later regret. But those upper body tattoos linger in ways one might not expect — the ink can actually show up on mammograms. As Generation X and Millennials have started undergoing breast cancer screenings, radiologists have been spotting pigment in lymph nodes more often.
“It’s so common actually that we now ask every women if they’ve had a tattoo,” Dr. Margarita Zuley, director of breast imaging at UPMC Magee Womens Hospital in Pittsburgh, told TODAY. “More women are getting tattoos than before. And as younger populations are aging into mammograms, which is for 40 and older, we are seeing more and more tattoos.”
An Ipsos poll from 2019 found that the number of Americans with tattoos has increased since 2012. About 30% of all Americans have one tattoo, which is up from 21% in 2012. But the number of people under 55 with tattoos is even higher. Thirty-six percent of people ages 35 to 54 have one tattoo. The number is even greater for people ages 18 to 34 with 40% of them having at least one.
Radiologists have certainly noticed this trend and see more people with tattoo pigment — which looks like white dots — in their lymph nodes. Mammograms don’t just create an image of the breast. They also provide a snapshot of what’s going on in the lymph nodes in the armpit.
“It’s important to include the lymph nodes because if there is a breast cancer, we want to know if it spread,” Dr. Susan Summerton, an associate professor of clinical radiology at the Perelman School of Medicine at the University of Pennsylvania, told TODAY. “Sometimes lymph nodes change and we see little white dots in them, which is typically what we call calcium deposits.”
Why does this happen?
Many things can cause white spots to appear. Some lotions, deodorants, prior illness, such as tuberculosis, and gold injections, used to treat rheumatoid arthritis, can also cause the dots that resemble calcification on mammograms. Because some cancers can also appear like white dots in mammograms, doctors do pay special attention to it.
“(The spots) could be tattooing. It could be calcium deposits from some metastatic cancers, like melanoma and ovarian cancer,” Zuley said.
But why it happens with tattoos has to do with how the immune system handles body art.
“The body reacts to that tattoo as if it’s a foreign body and it sends cells that help fight infection out to the tattoos,” Summerton explained. “It takes what it finds and carries it back to the lymph nodes. In the lymph nodes is typically where the infection or foreign body is handled.”
Only people with upper body tattoos, those on the breasts, arms, chest, neck, stomach and back would possibly have ink in the lymph node. Pigment for tattoos on the lower body would be found in the lymph nodes in the groin.
So, what does this mean for people with upper body tattoos?
Are tattoos impacting their health? The experts say, no.
“Tattoos have been around for generations. I’ve never heard of a cancer from coming from such a thing,” Zuley said. “The lymph nodes are meant to clear debris basically and just because the tattoo ink is sitting in the node doesn’t mean that it’s going to cause any harm.”
It doesn’t matter when people get the tattoo. The ink can pop up years after going under the needle.
“It could be 20 to 30 years later after a tattoo that you can see changes in the lymph nodes,” Summerton said. “I’m a breast imager so I care most about it because I see the tattoo pigment in lymph nodes in the armpit. But people are seeing it in other lymph nodes that are also tricking them into thinking that there’s a tumor, like they are a melanoma.”
Tattoo ink can also make the lymph nodes look darker, much like what happens with melanoma, a skin cancer. This might mean that doctors take out lymph nodes in patients with melanoma for further testing.
“When … there’s a reaction in the lymph nodes to the tattoo sometimes that dark pigment from the tattoo gets deposited and it looks dark,” Summerton said. “When they see the dark ones they think, ‘Oh this is melanoma in the lymph nodes.’”
Even if people report that they have a tattoo, if radiologists notice white spots on the lymph nodes or the nodes look darker they might be asked back for further testing. People might need to undergo an ultrasound or a biopsy. Without taking another look, doctors can’t be sure what it is.
But the experts stress that people shouldn’t be afraid to go for a follow-up — it's important to rule out cancer or catch cancer in early stages, when it's most treatable.
“Often we end up doing a biopsy of the lymph nodes to be sure. We need pathology results,” Zuley said. “Then once we know it’s there we ignore it.”