Myofibroblastic Proliferation as a Secondary Malignancy From Radioactive Iodine Treatment for Thyroid Carcinoma: A Case Report.

Thyroid carcinoma is an important health issue having significant morbidity and mortality. Management includes thyroidectomy followed by radioactive iodine ablation to kill any remaining tumor cells. However, the use of radioactive iodine ablation (RAI) is not without risks; one such risk is the development of secondary cancers, especially in patients undergoing radioactive iodine ablation at a younger age. We present a case of thyroid carcinoma where the patient was treated with radioactive iodine ablation over 20 years ago. The patient was recently found to have a neck mass, which was investigated with imaging and biopsied. Pathological findings were consistent with myofibroblastic proliferation, which is a benign abnormal growth of myofibroblasts but has small potential for malignant transformation. Management generally involves surgical excision, and other treatments like steroids, non-steroidal anti-inflammatory drugs, and radiation therapy can be used in select cases.