Arora Raman, Gupta Ruchika, Sharma Alok, Dinda Amit K
Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Indian J Pathol Microbiol. 2010 Jan-Mar;53(1):148-51. doi: 10.4103/0377-4929.59210.
Thymomas constitute majority of the thymic neoplasms. In contrast, neuroendocrine tumors (carcinoid and neuroendocrine carcinoma) of thymus are extremely rare. Thymic carcinoids may present rarely with Cushing's syndrome due to the ectopic production of adrenocorticotropic hormone (ACTH). Recognition of this association is imperative for appropriate management of patients. We describe three cases of rare atypical carcinoid tumor (neuroendocrine carcinoma) of the thymus. Case 1, of a 26-year-old man presenting with Cushing's syndrome, case 2--a 23-year-old female with Cushingoid features, and Case 3--a 39-year-old man complaining of progressively worsening dyspnea. Computed tomography (CT) scans of chest in all three patients revealed anterior mediastinal mass. Excision of tumors and histological examination of the three tumors showed a carcinoid tumor with nuclear pleomorphism, increased mitotic activity and focal necrosis. The features suggested a diagnosis of atypical carcinoid tumor in all the three cases. The tumor cells in Cases 1 and 2 showed focal immunohistochemical staining for ACTH. Atypical carcinoid (neuroendocrine carcinoma, well-differentiated and moderately-differentiated) of the thymus is a rare thymic tumor which carries a worse prognosis compared to thymoma and requires aggressive therapy. Hence, an accurate diagnosis is essential.
胸腺瘤是胸腺肿瘤的主要组成部分。相比之下，胸腺神经内分泌肿瘤（类癌和神经内分泌癌）极为罕见。胸腺类癌可能因异位分泌促肾上腺皮质激素（ACTH）而罕见地表现为库欣综合征。认识到这种关联对于患者的恰当管理至关重要。我们描述了3例罕见的胸腺非典型类癌肿瘤（神经内分泌癌）病例。病例1为一名26岁男性，表现为库欣综合征；病例2是一名23岁女性，具有类库欣特征；病例3是一名39岁男性，主诉进行性加重的呼吸困难。所有3例患者的胸部计算机断层扫描（CT）均显示前纵隔肿块。切除肿瘤并对这3个肿瘤进行组织学检查，结果显示为具有核多形性、有丝分裂活性增加和局灶性坏死的类癌肿瘤。这些特征提示所有3例均诊断为非典型类癌肿瘤。病例1和病例2的肿瘤细胞显示ACTH局灶性免疫组化染色。胸腺非典型类癌（神经内分泌癌，高分化和中分化）是一种罕见的胸腺肿瘤，与胸腺瘤相比预后较差，需要积极治疗。因此，准确诊断至关重要。
