Departments of Pathology and Neurological Surgery, University of Virginia School of Medicine, 1215 Lee Street-Room 3060-HEP, Charlottesville, VA, 22908-0214, USA.
Acta Neuropathol. 2017 Oct;134(4):521-535. doi: 10.1007/s00401-017-1769-8. Epub 2017 Aug 18.
The 4th edition of the World Health Organization (WHO) classification of endocrine tumors has been recently released. In this new edition, major changes are recommended in several areas of the classification of tumors of the anterior pituitary gland (adenophypophysis). The scope of the present manuscript is to summarize these recommended changes, emphasizing a few significant topics. These changes include the following: (1) a novel approach for classifying pituitary neuroendocrine tumors according to pituitary adenohypophyseal cell lineages; (2) changes to the histological grading of pituitary neuroendocrine tumors with the elimination of the term "atypical adenoma;" and (3) introduction of new entities like the pituitary blastoma and re-definition of old entities like the null-cell adenoma. This new classification is very practical and mostly based on immunohistochemistry for pituitary hormones, pituitary-specific transcription factors, and other immunohistochemical markers commonly used in pathology practice, not requiring routine ultrastructural analysis of the tumors. Evaluation of tumor proliferation potential, by mitotic count and Ki-67 labeling index, and tumor invasion is strongly recommended on individual case basis to identify clinically aggressive adenomas. In addition, the classification offers the treating clinical team information on tumor prognosis by identifying specific variants of adenomas associated with an elevated risk for recurrence. Changes in the classification of non-neuroendocrine tumors are also proposed, in particular those tumors arising in the posterior pituitary including pituicytoma, granular cell tumor of the posterior pituitary, and spindle cell oncocytoma. These changes endorse those previously published in the 2016 WHO classification of CNS tumors. Other tumors arising in the sellar region are also reviewed in detail including craniopharyngiomas, mesenchymal and stromal tumors, germ cell tumors, and hematopoietic tumors. It is hoped that the 2017 WHO classification of pituitary tumors will establish more biologically and clinically uniform groups of tumors, make it possible for practicing pathologists to better diagnose these tumors, and contribute to our understanding of clinical outcomes for patients harboring pituitary tumors.
世界卫生组织（WHO）第 4 版内分泌肿瘤分类最近发布。在这个新版本中，推荐对垂体腺（腺垂体）肿瘤分类的几个领域进行重大修改。本文的范围是总结这些推荐的变化，强调几个重要的主题。这些变化包括：（1）根据垂体腺神经内分泌细胞谱系对垂体神经内分泌肿瘤进行分类的新方法；（2）消除“非典型腺瘤”一词，对垂体神经内分泌肿瘤的组织学分级进行修改；（3）引入新实体，如垂体胚细胞瘤，并重新定义旧实体，如无细胞腺瘤。这种新的分类非常实用，主要基于垂体激素、垂体特异性转录因子和病理学实践中常用的其他免疫组织化学标志物进行免疫组织化学检测，而不需要对肿瘤进行常规超微结构分析。强烈建议根据肿瘤增殖潜能（通过有丝分裂计数和 Ki-67 标记指数）和肿瘤侵袭情况，对每个病例进行评估，以识别具有临床侵袭性的腺瘤。此外，通过确定与复发风险升高相关的特定腺瘤变体，该分类为治疗临床团队提供了有关肿瘤预后的信息。还提出了对非神经内分泌肿瘤分类的修改，特别是那些在后垂体中发生的肿瘤，包括垂体细胞瘤、后垂体颗粒细胞瘤和梭形细胞嗜酸性细胞瘤。这些变化与 2016 年 CNS 肿瘤 WHO 分类中发布的变化一致。还详细回顾了鞍区其他肿瘤，包括颅咽管瘤、间叶和基质肿瘤、生殖细胞肿瘤和造血肿瘤。希望 2017 年 WHO 垂体肿瘤分类能够建立更具生物学和临床一致性的肿瘤群体，使病理学家能够更好地诊断这些肿瘤，并有助于我们了解患有垂体肿瘤的患者的临床结果。
