Abstract
BACKGROUND: The incidence of Langerhans cell histiocytosis (LCH) is low, and involvement of the thyroid is even rarer, which results in high missed diagnosis or misdiagnosis rates. CASE SUMMARY: We report a young woman with a thyroid nodule. Thyroid malignancy was suggested by fine needle aspiration, but she was eventually diagnosed with multisystem LCH, thus avoiding thyroidectomy. CONCLUSION: The clinical manifestations of LCH involving the thyroid are atypical, and the diagnosis depends on pathology. Surgery is the main method for treating primary thyroid LCH, while chemotherapy is the main treatment method for multisystem LCH.