악성종양으로 오인된 전종격동의 이소성 갑상선 결절성 과증식증 1예

We describe a case of ectopic thyroid nodular hyperplasia, which mimicked a lymph node metastasis from a primary occult thyroid carcinoma. 50-year female was admitted to our clinic because of anterior mediastinal mass. On physical examination, there was a single, non-tender, firm swelling situated in the left supraclavicular region. Contrast-enhanced neck-chest CT showed about 5 cm-sized heterogeneous mass being strongly suspicious to malignancy such as a thymic carcinoma. PET-CT also revealed a circular lesion accompanied partially intense FDG uptake at the inferolateral area of left thyroid. Excision of the tumor was performed. Conventional biopsy proved a ectopic thyroid nodular hyperplasia which could mimic a metastasis of the thyroid carcinoma. Being aware of the possibility ectopic thyroid nodular hyperplasia is important so that unnecessary surgical assessment and undesirable sequelae should be avoided. (J Clinical Otolaryngol 2010;21:288-292)