Cutaneous pigmentation after photosensitivity induced by vandetanib therapy.

BACKGROUND Photosensitivity has been reported in patients who were treated with vandetanib (ZD6474), an inhibitor of epidermal growth factor receptor, vascular endothelial growth factor receptor, and the RET (rearranged during transfection) kinases. OBSERVATIONS We describe the occurrence of cutaneous hyperpigmentation after photosensitivity in 2 patients who were treated with vandetanib. The pigmentation patterns were variable within and between patients. Biopsy specimens from different sites revealed variability in Perls and Fontana staining patterns. CONCLUSIONS These 2 cases highlight the unusual occurrence of cutaneous hyperpigmentation after vandetanib-associated photosensitivity, a reaction that demonstrates that medications are important causes of acquired photosensitivity and hyperpigmentation. Aggressive photoprotection may facilitate the resolution of diffuse hyperpigmentation. Dermatologists should endeavor to identify and report novel cutaneous adverse effects as new targeted therapies are developed.