RADIATION-INDUCED PAPILLARY THYROID CARCINOMA IN A PEDIATRIC BRAIN TUMOR SURVIVOR

Secondary malignant neoplasms are a rare but feared late complication of pediatric cancers. Radiation therapy is a well-established risk factor for the development of thyroid tumors, particularly in children, whose thyroid gland is sensitive to the carcinogenic effects of ionizing radiation.This is the case of a 16-year-old female patient who was diagnosed at the age of 5 with a medulloblastoma of the posterior cranial fossa, which was surgically treated and irradiated. Ten years later, a cervical mass developed, leading to the diagnosis of papillary thyroid carcinoma (PTC) with lymph node involvement. Pulmonary nodules/micronodules were identified,consistent with hematogenous dissemination. The patient received two doses of radioactive iodine therapy, in the context of an elevated postoperative thyroglobulin level. Follow-up chest CT revealed progression of a suspicious right lower lobe pulmonary micronodule, while whole-body scintigraphy showed multiple iodine-avid foci.This case highlights the need for long-term surveillance in pediatric cancer survivors due to the elevated risk of radiationinduced secondary thyroid malignancies.