FDG PET/CT Detected Thymic Lymphoepithelioma-Like Carcinoma

正子電腦斷層攝影發現胸線淋巴上皮瘤樣癌

林聖哲(Sheng-Che Lin) ； 陳世緯(Shih-Wei Chen) ； 陳遠光(Yen-Kung Chen) ； 葉加祿(Chia-Lu Yeh)

《核子醫學暨分子影像雜誌》 30卷3期 (2017/09) Pp. 118-122

https://doi.org/10.6332/ANMMI.3003.003

摘要

Thymic tumors account for approximately 50% of anterior mediastinal lesions. The incidence of thymoma is approximately 0.15 cases per 100,000 populations. Approximately two thirds of patients are asymptomatic at diagnosis. 2-deoxy-2-[18F]fluoroglucose (F-18 FDG)/ positron emission tomography (PET) may be useful for predicting the grade of malignancy in thymic epithelial tumors. A soft-tissue nodule with mildly increased FDG uptake in the left anterior mediastinum was found in a whole-body FDG PFT/computed tomography (CT) scan in a 74-year-old male who underwent check-up. Thymoma was considered first and surgical removal was performed. The pathologic examination showed a thymic lymphoepithelioma-like carcinoma (LELC) and it extended through the capsule into the surrounding soft tissue. Thymic LELC is a histological subtype of aggressive thymic carcinoma. The prognosis of this type is poor with an estimated mean survival of 18.7 months. However, the maximum standardized uptake value (SUVmax) in our patient was relatively lower than expected, possibly due to small size or early stage of disease. Medical research surrounding the pathogenesis and image feature of thymic LELC was limited, and further investigation is needed.

關鍵字

F-18 FDG PET/CT ； thymic LELC ； thymoma

並列摘要

胸腺腫瘤約佔前縱隔腔腫瘤的50%。胸腺瘤的盛行率約為0.15/10 萬人。大約三分之二的病例在確診時沒有症狀。而過去的研究認為 氟 -18 氟化去氧葡萄糖正子電腦斷層攝影對於預測胸腺瘤的惡性程度有幫助。一位74 歲男性接受全身的氟 -18 氟化去氧葡萄糖正子電腦斷層攝影，發現前縱隔腔左側有一個軟組織結節合併葡萄糖攝取增加。初步懷疑是胸腺瘤並手術切除。病理報告顯示該病灶為胸線淋巴上皮瘤樣癌，而且侵犯莢膜及腫瘤周圍組織。胸線淋巴上皮瘤樣癌為較少見的原發的來自胸腺上皮惡性腫瘤，是胸線癌中比較惡性的一種，平均的存活時間約為18.7 個月。但是我們的病例可能因為大小比較小或是較為早期的緣故，最大標準攝取值 (SUV_(max)) 沒有預期的高。目前對於胸線淋巴上皮瘤樣癌的病理及影像方面的研究還很有限，還需要將來更進一步的研究。

並列關鍵字

氟 -18 氟化去氧葡萄糖正子電腦斷層攝影 ； 胸線淋巴上皮瘤樣癌 ； 胸腺瘤