Multiple Radioiodine-avid Skin Metastases From Thyroid Carcinoma Detected on Posttherapy 131I SPECT/CT

A 77-year-old man with papillary thyroid carcinoma had received radioactive iodine therapy for metastatic disease 8 years earlier and subsequently achieved remission. He represented with rising serum thyroglobulin levels, and biopsy of newly detected cutaneous lesions confirmed metastatic disease. Posttherapy ¹³¹ I SPECT/CT after 200 mCi demonstrated multiple radioiodine-avid cutaneous metastases involving the scalp, left auricular region, anterior chest wall, and dorsal region. This case highlights an exceptionally uncommon presentation of extensive, multifocal, radioiodine-avid cutaneous metastases detected on post-therapy ¹³¹ I SPECT/CT after a long disease-free interval.