微小癌を合併した自律性機能性甲状腺結節

抄録

We report a case of autonomously functioning thyroid nodule (AFTN) with papillary microcarcinoma in a 74-year-old woman. She complained of a right anterior neck mass, and presented with hyperthyroidism. Computed tomography and magnetic resonance imaging of the thyroid showed a nodule measuring 2.5×2cm in the right lobe and a nodule measuring 5×4.5cm in the left lobe. The left lobe nodule was hyperfunctioning on Tc-99m imaging. On the other hand, the right lobe nodule showed uptake on delayed T1-201 imaging and was suggested to be malignant. Fine needle aspiration biopsy using ultrasonography was class V (papillary carcinoma) for the right lobe nodule and class II for the left lobe nodule. The patient underwent total thyroidectomy and right regional neck dissection. Histopathological examination revealed two papillary microcarcinomas (each 5mm in diameter) surrounded by nodular hyperplasia in the right lobe, nodular hyperplasia in the left lobe, and right pretracheal and paratracheal lymph node metastasis. Since it is not rare for cancer to be associated with AFTN, care must be taken to obtain an accurate diagnosis in such cases and surgery is the treatment of choice for AFTN.