Klemm K M, Moran C A
Department of Pathology, The University of Alabama at Birmingham, 35294, USA.
Semin Diagn Pathol. 1999 Feb;16(1):32-41.
Primary neuroendocrine carcinomas of the thymus are rare and comprise a wide spectrum of lesions ranging from well-differentiated to poorly-differentiated neoplasms. The classification of such tumors in the thymus is still controversial. By convention, the better-differentiated examples have been traditionally designated as thymic carcinoids and thought to represent the mediastinal counterpart of carcinoid tumors in other foregut locations. However, recent studies have shown that such neoplasms, when arising in the thymus, exhibit a much more aggressive behavior than those originating at other locations. We therefore consider these lesions to represent fully malignant neoplasms that fall within the spectrum of neuroendocrine carcinomas. The designation of well-, moderately-, or poorly-differentiated thymic neuroendocrine carcinoma is therefore favored for these tumors in the present review. Because such tumors may often adopt unusual morphological appearances, it is important to distinguish them from other more common conditions presenting at this location that may exhibit similar histological features. The clinicopathologic, immunohistochemical, and differential diagnostic features of these tumors in the mediastinum are discussed.
胸腺原发性神经内分泌癌较为罕见，包括从高分化到低分化肿瘤的广泛病变谱。此类胸腺肿瘤的分类仍存在争议。按照惯例，高分化的病例传统上被指定为胸腺类癌，并被认为是其他前肠部位类癌肿瘤的纵隔对应物。然而，最近的研究表明，此类肿瘤发生于胸腺时，其行为比起源于其他部位的肿瘤更具侵袭性。因此，我们认为这些病变代表了属于神经内分泌癌谱的完全恶性肿瘤。因此，在本综述中，对于这些肿瘤，倾向于使用高分化、中分化或低分化胸腺神经内分泌癌的命名。由于此类肿瘤可能常呈现不寻常的形态学表现，将它们与该部位其他可能表现出相似组织学特征的更常见情况相区分很重要。本文讨论了这些纵隔肿瘤的临床病理、免疫组化及鉴别诊断特征。
