Foreign bodies in the thyroid gland and foreign body reactions in the post-thyroidectomy bed

Foreign bodies (FBs) in the thyroid gland are very rare and may create diagnostic and therapeutic problems. So far, there have been a few review articles concerning only ingested FBs in the thyroid gland, while other mechanisms remain poorly studied. FB reactions mimicking thyroid regrowth in the post-thyroidectomy bed may also pose a diagnostic challenge for clinicians due to their rarity. The article discusses ingested, traumatic, and iatrogenic FBs in the thyroid gland. Our search generated 56 relevant articles with 63 total cases of FBs in the thyroid gland. The review highlights the clinical presentation, the most useful diagnostic methods, and treatment modalities. The vast majority of the FBs in the thyroid gland were fish bones (63.5%). The analysis shows that over one-third of the patients may be misdiagnosed at the initial evaluation. Moreover, tissue responses to the foreign materials in the post-thyroidectomy bed mimicking actual FBs are described with particular attention to the diagnostic imaging and histopathologic findings. FBs in the thyroid gland and FB reactions in the post-thyroidectomy bed represent rare challenges that require prompt management. Although these medical conditions are very rare, they can lead to many diagnostic difficulties, which may influence the patient's care.