mesotheliomas

Mesothelioma is a malignant tumor that originates from mesothelial cells lining serous membranes. The majority arises in the pleura, the lining of the lungs, but mesothelioma can also develop in the peritoneum, pericardium, or tunica vaginalis. It is strongly associated with asbestos exposure, with a long latency period that often spans decades. The disease is rare but aggressive.

Most cases are linked to asbestos, with amphibole forms considered particularly potent. Other risk factors include prior therapeutic radiation and certain genetic predispositions, such as BAP1 mutations. Smoking does not by itself cause mesothelioma but can worsen risk in those exposed to asbestos.

Symptoms depend on the site of disease. Pleural mesothelioma may cause chest pain, shortness of breath, and pleural effusion; peritoneal disease can present with abdominal distension, pain, and weight loss. Diagnosis relies on imaging (usually CT or MRI), tissue biopsy, and histology with immunohistochemistry to distinguish mesothelioma from metastatic carcinoma. Immunohistochemical patterns commonly include positivity for calretinin and WT-1 and negativity for CEA.

Treatment is multidisciplinary and stage- and histology-dependent. Options include surgery (pleurectomy/decortication or, in selected cases, extrapleural pneumonectomy), systemic chemotherapy (pemetrexed with a platinum agent such as cisplatin or carboplatin), and, in some regimens, antiangiogenic therapy such as bevacizumab. Radiation therapy may be used for palliation or local control. Peritoneal mesothelioma is sometimes managed with cytoreductive surgery and HIPEC. Prognosis remains generally poor, with median survival around a year for pleural disease, influenced by histology and treatment.

Epidemiology and prevention: asbestos exposure is the main cause; bans and restrictions exist in many countries. Mesothelioma occurs more often in men with a history of occupational exposure.