原發性甲狀腺淋巴瘤是一少見的惡性腫瘤，大約占所有甲狀腺癌症中不到2%。我們報 告一例右側甲狀腺腫大但手術後發現左側甲狀腺有淋巴瘤的罕見案例。一位五十四歲女性， 近幾個月因吞嚥不適及頸部甲狀腺腫大就診，身體檢查發現右頸部有一直徑約兩公分之甲狀 腺結節，甲狀腺功能正常，頸部超音波發現兩側有多發性低回音性結節，最大結節直徑約1.9 公分位於右葉，施行細針吸引細胞學檢查，病理報告為濾泡病灶(follicular lesion)，經甲狀 腺手術後，將右側甲狀腺全切除，病理報告為橋本氏甲狀腺炎，以及左側甲狀腺次全切除， 其中有一直徑約兩公分切面呈灰棕褐色團塊，診斷為惡性淋巴瘤( 瀰漫性大B 細胞淋巴瘤， diffuse large B-cell type)。術後恢復情況良好，建議病人轉診至血液腫瘤科進一步評估治療。

Thyroid lymphomas are rare, accounting for less than 2% of thyroid malignancies. We report a rare case of a 54-year-old female patient presenting with right neck enlargement and subsequent subtotal thyroidectomy showing lymphoma in the left lobe of thyroid. The patient presented initially with neck enlargement and dysphagia. Physical examination revealed a goiter measuring about 2 cm over the right anterior neck. Thyroid function test was normal. Ultrasonography of thyroid revealed multiple hypoechoic lesions bilaterally, with the largest measuring 19mm in the right lobe. Fine needle aspiration revealed follicular lesions. The patient underwent right total lobectomy, with pathology showing Hashimoto’s thyroiditis, and left subtotal lobectomy, showing a 2 cm tan gray lesion with histopathology consistent with malignant lymphoma, diffuse large B-cell type. The patient recovered very well postoperatively, and was referred to hematology for further evaluation and treatment.