A 15-year-old back tattoo is being blamed for a woman's cancer-like symptoms.
Large, dark lumps were found under the armpits of a 30-year-old Australian woman, which doctors suspected looked like lymphoma.
In fact, it was a reaction with black tattoo ink.
Doctors at the Royal Prince Alfred Hospital in Sydney removed the lymph node from her armpit and found a cluster of cells filled with black pigment.
They said the case highlights "the importance of a careful tattoo history and physical examination for cases of lymphadenopathy".
Dunedin gastroenterologist Dr Steve Johnson said it was not common, but it has been reported for a number of years.
"You can get localised swelling, granulomas, or little nodules over your tattoo site. Or you can develop these enlarged lymph nodes," he said.
"Considering the number of people who get tattoos, this is actually a fairly rare complication."
New Zealand is one of the most-inked nations in the world, with one in five Kiwis having a tattoo.
It's a piece of art, so you have to look after it- Te Kanawa Ngarotata, Auckland tattoo artist
Health risks usually involved infection around the time of tattooing, or complications involving the dye or ink, Dr Johnson said.
Te Kanawa Ngarotata, a tattoo artist at Otautahi Tattoo on Auckland's Karangahape Rd, told 1 NEWS health and safety is a key component of the procedure.
"Because you're opening up skin, it's similar to surgery. There are a lot of things that could happen, so it's better just to avoid [it] by being sterile, not cross-contaminating," he said.
"[After tattooing] we'll sit people down, talk to them to let them know you can't have their tattoo submerged underwater.
"A lot of anti-bacterial creams are used. Some people recommend you keep it clean and moist. It's up to the tattooist to let the person know."
Different types of tattoos could require a more attention, he said.
"Moko is a lot of line work, it's heavy details. It requires a different sort of after-care.
"It's a piece of art, so you have to look after it."