A Swedish study tied tattoos to 21 percent more lymphoma

Researchers at Lund University in Sweden compared tattoo histories in 1,398 people diagnosed with lymphoma between 2007 and 2017 against 4,193 controls, matched for age and sex, drawn from Swedish national health registers.

Tattooed people had about a 21 percent higher adjusted risk of lymphoma than people without tattoos. The risk was highest in people tattooed less than two years before diagnosis, dropped at three to ten years, then rose again at eleven or more years, with no added risk from a larger tattooed area.

The confidence interval on the main 21 percent figure touched 1, meaning the result sits on the edge of statistical significance from a single study, and the authors themselves called for more research before drawing firm conclusions. Ink deposits reaching lymph nodes is documented; whether that deposit triggers lymphoma, or simply travels there alongside some other risk factor, is still unresolved.

A needle's ink reached further than the skin.