甲状腺手術から6年後に肺転移で診断された甲状腺濾胞癌の1例

Follicular Thyroid Carcinoma Diagnosed with Lung Metastasis Six Years After Thyroid Surgery：Report of a Case

はじめに　甲状腺濾胞腺腫と甲状腺濾胞癌の鑑別は，病理学的にも困難とされている1）．われわれは，甲状腺濾胞腺腫手術から6年後に肺転移で甲状腺濾胞癌と診断しえた症例を経験したため報告する．

A 72-year-old man was diagnosed with gastric cancer. Preoperative chest computed tomography （CT） revealed three nodules in the right lung. The patient had no history of malignant disease and had undergone surgery for thyroid follicular adenoma six years previously. Based on the morphology of the nodules, the right lower lobe nodule was suspected to be a primary lung cancer, whereas the right upper and middle lobe nodules were suspected to be lung metastases secondary to lung or gastric cancer. After distal gastrectomy, thoracoscopic wedge resection was performed for the pulmonary nodules. The right lower lobe pulmonary nodule was diagnosed as primary lung cancer, and the right upper and middle lobe pulmonary nodules were diagnosed as lung metastases from thyroid follicular carcinoma. When a patient with a history of thyroid follicular adenoma presents with a lung nodule, lung metastasis from thyroid follicular carcinoma should be considered.