It’s hard to understand how or why cancer in one part of the body can have effects on an entirely different part of the body—but that’s exactly what happened to one woman who, after noticing her palms looked odd, was eventually diagnosed with lung cancer.

The story comes from a new case study published in the The New England Journal of Medicine, which follows a 73-year-old woman, who first presented to a dermatology clinic with “pruritic (itchy) and painful lesions” on the palms of her hands.