ABSTRACT Fibroblast growth factor receptor (FGFR) inhibitors are effective in malignancies with FGFR pathway alterations but may disrupt calcium‐phosphate metabolism, leading to dermatologic side effects. We report a case of calcinosis cutis presenting as painful flexural plaques in a 16‐year‐old patient treated with erdafitinib for high‐grade glioma. The patient's age, unusual lesion distribution, and spontaneous resolution after drug discontinuation highlight a previously unreported association in pediatrics. Recognizing this potential adverse effect may help avoid unnecessary diagnostic or therapeutic interventions.
Benito‐Mendieta et al. (Sun,) studied this question.