Acute Kidney Injury After Thyroid Hormone Withdrawal in an Adolescent with Papillary Thyroid Carcinoma.

Objectives:We report a patient with papillary thyroid carcinoma (PTC) who developed acute kidney injury (AKI) and elevated creatine kinase (CK) after thyroid hormone withdrawal (THW) prior to radioiodine therapy. Case presentation:A 12-year-old female patient who had undergone total thyroidectomy for PTC one year ago presented with leg pain for the past 2 days. Following THW 3 weeks ago, the case had received 70 mCI radioiodine treatment 6 days ago. Serum creatinine (1.53 mg/dL, normal range [NR]: 0.3-1.1), aspartate aminotransferase (102 IU/L, NR: 0-40) and CK (3451 IU/L, NR: 26-174) levels were elevated. Thyrotropin level was elevated (>100 µIU/ml, NR: 0.51-4.3), and free T4 level was decreased (0.05 ng/dL, NR: 0.98-1.63). Serum creatinine and CK levels decreased after intravenous hydration and levothyroxine treatment. Conclusion:In PTC cases with thyroidectomy, kidney function and CK elevation should be assessed after THW and dehydration should be prevented.