**1. Introduction**

Malignant mesothelioma (MM) is a rare and aggressive cancer that affects the mesothelial cells lining the serosal membranes of body cavities, such as the pleura (83% of cases), peritoneum (11%), pericardium, and tunica vaginalis (1–2%) [1–3]. MM is histologically classified into three types—epithelioid accounting for 80% of the cases, sarcomatoid accounting for more than 10%, and biphasic, which has both epithelioid and sarcomatoid features [4, 5]. The epithelioid subtype is associated with a better prognosis compared to sarcomatoid and biphasic subtypes [5, 6]. Histology and TNM (tumor lymph nodes metastasis) staging are the main prognostic factors and the prognosis remains poor with a median survival from 4 to 19 months [5].

A total of 80% of MM cases concern the pleura and the main cause is asbestos exposure [1]. Approximately 50% of patients with MM have a history of prior asbestos exposure [7]. The median age of diagnosis is 75 years of age and the latency period (the period from the initial asbestos exposure until the diagnosis of mesothelioma) is around 30–40 years [8]. The incidence of mesothelioma is still increasing, despite the wide prohibition of asbestos use. Except for asbestos, exposure to other mineral fibers having similar characteristics, such as erionite or fluoro-edenite, has been implicated in the development of MM [1]. A limited number of MMs are attributed to exposure to ionizing radiation for diagnostic or therapeutic purposes. Asbestos has been widely used for decades globally and 10–17% of those highly exposed to asbestos develop MM [9]. This observation has led to the hypothesis that a possible role of genetic risk factors modifies the effect of asbestos exposure [1]. Recent studies have suggested germline mutations in DNA repairs genes, such as BAP1 (BRCA-1-associated protein) in patients with pleural MM [10, 11]. Approximately 21–63% of MMs involve BAP1 somatic or germline mutations, while 22% of patients with BAP1 mutations will develop MM at some point [2].

During the last years, there have been advances in the understanding of the biology and pathogenesis of mesothelioma. The pathogenesis of MM is thought to be multifactorial and a better understanding of the pathogenetic mechanisms may enable the identification of efficient and personalized treatment patterns for precision medicine. The purpose of our study is to present the causes of mesothelioma by enriching them with the latest data and also describe the possible pathogenetic mechanisms for the development of this insidious cancer.
