Sara de Benito‐Mendieta, S. Casado Buendía, Lucero Noguera‐Morel, Isabel Colmenero, Olga Suárez‐Traba, Á. Hernández‐Martín
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.