Malignant pleural mesothelioma (MPM) still represents a complex diagnostic challenge for pathologists in routine practice. This diagnosis requires a multidisciplinary approach, and pathological evaluation is mandatory. The histopathological diagnosis is stepwise and should be based on morphological and immunohistochemical assessment, sometimes associated with molecular tests, and supported by clinical and radiological findings. A correct morphological approach aims to exclude pleural metastasis or benign mesothelial proliferations, which are the main differential diagnoses. While certain histological features are diagnostic of MPM, others are highly suggestive but not definitive. Immunohistochemistry plays a pivotal role, with a panel of both traditional and newer markers being used to assess mesothelial differentiation and to differentiate malignant from benign proliferations. In more challenging cases, molecular tests, such as fluorescent in situ hybridization (FISH) to detect CDKN2A deletion, can be helpful in distinguishing malignant from benign pleural lesions. This review summarizes the key morphological, immunohistochemical, and molecular features that should be considered when pleural biopsy samples are examined, with the aim of improving diagnostic accuracy in this complex area.
恶性胸膜间皮瘤（MPM）在常规病理实践中仍是一个复杂的诊断难题。该诊断需采用多学科方法，且必须进行病理学评估。组织病理学诊断应分步进行，需基于形态学与免疫组化评估，有时需结合分子检测，并需临床与影像学发现的支持。正确的形态学分析旨在排除胸膜转移瘤或良性间皮增生——这两者是主要的鉴别诊断。虽然某些组织学特征可确诊MPM，但另一些特征虽高度提示却非确定性依据。免疫组化发挥着关键作用，通过组合使用传统与新型标志物来评估间皮分化并鉴别良恶性增生。对于更具挑战性的病例，分子检测（如通过荧光原位杂交检测CDKN2A缺失）有助于区分良恶性胸膜病变。本综述总结了胸膜活检样本检测中应考虑的关键形态学、免疫组化及分子特征，旨在提升这一复杂领域的诊断准确性。
Diagnostic Challenges in the Pathological Approach to Pleural Mesothelioma
肿瘤(癌症)患者之家