Dacic Sanja
Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Mod Pathol. 2022 Jan;35(Suppl 1):51-56. doi: 10.1038/s41379-021-00895-7. Epub 2021 Aug 31.
Mesothelial tumors are classified into benign or preinvasive tumors, and mesotheliomas. The benign or preinvasive group includes adenomatoid tumors, well-differentiated papillary mesothelial tumors, and mesothelioma in situ. Malignant tumors are mesotheliomas and can be localized or diffuse. Histological classification of invasive mesotheliomas into three major subtypes-epithelioid, sarcomatoid, and biphasic is prognostically important. It also plays a significant role in the treatment decisions of patients diagnosed with this deadly disease. Grading and subtyping of epithelioid mesotheliomas have been one of the major changes in the recent WHO classification of pleural tumors. Mesothelioma in situ has emerged as a precisely defined clinico-pathologic entity that for diagnosis requires demonstration of loss of BAP1 or MTAP by immunohistochemistry, or CDKN2A homozygous deletion by FISH. The use of these two biomarkers improves the diagnostic sensitivity of effusion specimens and limited tissue samples and is valuable in establishing the diagnosis of epithelioid mesothelioma. In this review, recent changes in the histologic classification of pleural mesothelioma, importance of ancillary diagnostic studies, and molecular characteristics of mesotheliomas are discussed.
间皮肿瘤分为良性或侵袭前肿瘤以及间皮瘤。良性或侵袭前肿瘤组包括腺瘤样肿瘤、高分化乳头状间皮肿瘤和原位间皮瘤。恶性肿瘤为间皮瘤，可局限或弥漫性生长。将侵袭性间皮瘤组织学分类为三种主要亚型——上皮样、肉瘤样和双向型，在预后方面具有重要意义。它在诊断患有这种致命疾病的患者的治疗决策中也起着重要作用。上皮样间皮瘤的分级和亚型划分是近期世界卫生组织胸膜肿瘤分类中的主要变化之一。原位间皮瘤已成为一个精确界定的临床病理实体，其诊断需要通过免疫组织化学证明BAP1或MTAP缺失，或通过荧光原位杂交证明CDKN2A纯合缺失。这两种生物标志物的应用提高了积液标本和有限组织样本的诊断敏感性，对确立上皮样间皮瘤的诊断很有价值。在本综述中，讨论了胸膜间皮瘤组织学分类的近期变化、辅助诊断研究的重要性以及间皮瘤的分子特征。
