Mesothelial Tumors of the Pleura

Primary tumors of the pleura are relatively rare lesions, being far outnumbered by metastatic disease to the pleural surfaces. Tumors of mesothelial origin represent a subgroup of these tumors and malignant mesothelioma is the most common primary malignant neoplasm of the pleural surfaces. Malignant mesothelioma is a highly aggressive malignancy that responds poorly to treatment and has a dismal overall survival (Zellos and Sugarbaker, Semin Oncol 29:41-50, 2002; Edwards et al., Thorax 55:731-5, 2000; Scherpereel et al., Eur Respir J 35:479-95, 2010). Malignant mesothelioma is a heterogeneous disease with different histological patterns and genomic characteristics. The vast majority of cases are attributable to asbestos exposure and typically develop after a long latency period (Wagner et al., Br J Ind Med 17:260-71, 1960; Astoul et al., Respiration 83:481-93, 2012). This long latency is to blame for the rising incidence of mesothelioma cases, despite the ban of mining, processing, and use of asbestos in many industrialized countries. Studies with the aim of identifying targetable mutations in mesothelioma are currently ongoing as novel therapeutic strategies are being sought. Benign mesothelial tumors, on the other hand, are extremely rare in the pleural cavity despite their more frequent occurrence in other mesothelial-lined spaces, such as the peritoneum or the genitourinary tract.