Radioiodine uptake in A Renal CYST in A Patient with Papillary Thyroid Carcinoma

Abstract

ABSTRACT Objective: To present a case of papillary thyroid cancer (PTC) with radioiodine (RAI) uptake in a benign renal cyst on the posttherapy whole-body scan (pT-WBS). Methods: The clinical course and diagnostic findings are described for a patient with PTC postthyroidectomy, who was found to have RAI uptake in a benign renal cyst after thyroid remnant ablation (TRA). In addition, a literature review regarding iodine uptake in nonthyroidal tissues is presented. Results: With a negative diagnostic scan for PTC postthyroidectomy, our patient underwent RAI TRA with subsequent unexpected uptake in the left posterior upper quadrant of the abdomen on the pT-WBS. Single-photon emission computed tomography/computed tomography imaging delineated the area to the left kidney. On further sonographic imaging, a simple cyst was seen in the suspected area, with no evidence of metastatic lesions. Conclusion: RAI has been used diagnostically to recognize, as well as therapeutically treat, thyroid remnants and distant io...