Clinical significance of histologic subtyping of malignant pleural mesothelioma

Abstract

Malignant mesothelioma (MM) is uncommon, but very aggressive tumor arising from the mesothelial cells of pleura, pericardium, peritoneum, and tunica vaginalis. Despite multimodality treatments 5-year survival is only 5% after the diagnosis. Histology and TNM staging system are still the best prognostic factors. Furthermore, histologic subtype of MM determines the clinical management of the patients. According to the 2015 WHO classification, MM is divided into diffuse, localized and well differentiated papillary mesothelioma. Major histologic subtypes of diffuse MM, namely epithelioid, biphasic and sarcomatoid, have different prognosis. However, in the last decade it has become evident that more detailed subclassification and histologic/cytological characterization of MM have prognostic and perhaps predictive implications. In this review, major histologic subtypes and cytological features of MM are presented and their relation with prognosis and predictive biomarkers is discussed.

Metastasis of Sarcomatoid Malignant Mesothelioma With p16/CDKN2A Deletion Presented as a Subcutaneous Mass in the Back: a Case Report and Review of Literature

“…PD-L1 expression is relatively common (> 30%) for MM samples [42], and it is related to poor prognosis in MM patients [43]. Immunotherapy such as nivolumab is being on clinical trials as a second or third line treatment for MM [2,44]. In this case, the mediastinal and right infraclavicular lymph nodes seemed sensitive to cytotoxic agents, however, the pulmonary nodule and the subcutaneous mass were both resistant to the agents.…”

“…It has been increasing over the past decade, and most cases are associated with exposure to asbestos. It is divided into three subtypes: epithelioid type, sarcomatoid type and biphasic type [2], and sarcomatoid MM is the most aggressive type. It is usually di cult to differentiate from benign mesothelial pleural proliferations or other cancers [3].…”

Digital Gene Expression Analysis of Epithelioid and Sarcomatoid Mesothelioma Reveals Differences in Immunogenicity

“…Generally, MPM can be differentiated into three major histologic subtypes, epithelioid (EMM), sarcomatoid (SMM), and biphasic (BMM). EMM accounts for up to 80% of all MPM cases [6]. It has also a more favorable outcome compared with the SMM or BMM, especially when surgery is applied [7].…”

“…It has also a more favorable outcome compared with the SMM or BMM, especially when surgery is applied [7]. Though it needs to be noted that epithelioid morphology can differ greatly [6,8], thereby also impacting clinical outcome [9][10][11]. The sarcomatoid subtype is the least prevalent subtype of mesothelioma (<10%) [8].…”

“…The sarcomatoid subtype is the least prevalent subtype of mesothelioma (<10%) [8]. SMM is considered to be more aggressive in a clinical setting with a higher tendency of distant metastasis [6,12]. The BMM has a mixed composition of both epithelioid and sarcomatoid histology [8].…”