Development of Abnormal Pigmentation of the Oral Mucosa Following Adjuvant Radioactive Iodine Treatment

ABSTRACT Objective: We report the case of a 52-year-old black woman who developed discoloration of her tongue following radioactive iodine (RAI) ablation. RAI is a common method of treatment for a number of thyroid disorders, including thyroid malignancies and hyperthyroidism. Common side effects of this therapy include hypothyroidism, changes in taste, nausea, and sialadenitis. Methods: This is an Institutional Review Board–approved single-case chart review with a patient consent. Results: The patient presented with no changes in oral sensation and mild diffuse elongation of the filiform papillae with diffuse, symmetrical, black pigmentation in the distribution of the fungiform papillae 9 days following treatment with RAI. There were no new exposures known to cause a similar reaction, and she had not changed her diet or oral hygiene habits during the development of this symptom. Conclusion: To our knowledge, this is the first documented case of pigmentation change to the tongue following treatment with RAI. While this is a novel documentation of an adverse event, we encourage providers to be observant for such presentation in their patients treated with RAI. Abbreviations: RAI = radioactive iodine