摘要
胸腺腫瘤(thymic tumor)是相當少見的腫瘤，好發於前縱膈腔，約佔所有癌症發生率的0.2%-1.5%，西方國家發生率約十萬分之0.15，台灣每年有將近150位新診斷個案，發生率約爲每十萬人0.63個案數。胸腺腫瘤變異性很大，依據上皮細胞的分化程度分爲相對良性的胸腺瘤(thymoma)和極端惡性的胸腺癌(thymic carcinoma)。胸腺瘤的病理切片呈良性細胞分化，細胞生長慢，但實際臨床表現具惡性度，會侵犯局部組織，少數會轉移至肋膜或胸腔，診斷時半數病患並無臨床症狀，約1/3至1/2病患會伴有副腫瘤症候群(paraneoplastic syndrome)，常見的副腫瘤症候群包含重症肌無力、純紅血球再生不良和低丙型球蛋白血症。胸腺癌不管細胞分化或臨床表現皆具高度侵犯性，約80%病患有咳嗽、胸痛、橫膈神經痲痺、上腔靜脈阻塞或遠處轉移引起的不適，罕見伴有副腫瘤症候群。胸腺腫瘤的分期包括WHO的細胞組織型態分類及Masaoka臨床分期，兩者皆可有效判斷病患的手術切除率及預後。手術切除是治療胸腺腫瘤首選的方式，能否完全手術切除更是最關鍵的預後因子。對於局部晚期(locally advanced)的病患，無法完全手術切除，此時以化學治療加上手術切除及術後放射線治療的整合性治療，可以有效提升完全手術切除機會同時提高存活率。
並列摘要
Thymic tumor arises from the epithelial cells of the thymus. It is an uncommon malignancy comprising 0.2-1.5% of all malignancies, and 90% of them occur in the anterior mediastinum. Approximately 150 patients were diagnosed in Taiwan every year; the indicience was 0.63 cases per 100,000 populations. Thymic tumors are broadly classified into thymoma and thymic carcinoma. Thymoma is an indolent tumor of local invasion to pleural cavity potential. More than half of all patients are asymptomatic at the diagnoses. One third to half of patients present with symptoms related to paraneoplastic syndrome. The most common ones are myathensia gravis, pure red cell aplasia and hypogammaglonulinemia. In contrast to thymoma, thymic carcinoma is more malignant and carrier early distant metastases potential, and more than 80% of patients are symptomatic at the time of presentation. Paraneoplastic syndromes are uncommon in thymic carcinoma. The Masaoka staging system and WHO morphological classification are the most commonly used systems to assess prognoses of the thymic tumors. Complete surgical resection is the most important prognostic factor, but difficult to achieve in locally advanced thymic tumors. The multimodality therapy combining neoadjuvant chemotherapy followed by surgery and post-operative radiotherapy is by far the best treatment for locally advanced thymic tumors to date.