Asbestos-induced peritoneal mesothelioma in a construction worker

Occupational and environmental asbestos exposure continues to represent a public health problem, despite increasingly restrictive laws adopted by most industrialized countries. Peritoneal mesothelioma is a rare and aggressive asbestos-related malignancy. We present a 65-year-old man who developed recurrent ascites after having been exposed to asbestos in the building industry for over 40 years. Liver function and histology were normal. Abdominal computed tomography initially excluded the presence of expansive processes, and no abnormal cells were found in the ascitic fluid. Laparoscopy showed diffuse neoplastic infiltration of the peritoneum. Bioptic samples histopathology revealed epithelioid neoplastic proliferation with a tubulopapillary pattern, falsely suggesting metastatic adenocarcinomatosis. In consideration of the occupational history, and after further diagnostic procedures had failed to identify the hypothetical primitive tumor, immunostaining of the neoplastic tissue was performed. The carcinoembrionary antigen (CEA) and the epithelial glycoprotein Ber-EP4 were negative, while the mesothelial markers cytokeratins, calretinin, epithelial membrane antigen (EMA) and HBME-1 resulted positive, leading to the correct diagnosis of peritoneal epithelial mesothelioma. The Italian Workers’ Compensation Authority (INAIL) recognized the occupational origin of the disease. Cytoreductive surgery associated with continuos hyperthermic peritoneal perfusion (cisplatin at 42°C, for an hour) was performed. The disease relapsed after four months, and was later complicated by bowel obstruction requiring palliative ileostomy. The patient died 23 months after diagnosis. The case illustrates the insidious diagnostic problems posed by peritoneal mesothelioma, a tumor which often simulate other malignancies (e.g., metastatic carcinomas) at routine histopathological examination. Occupational history and immunohistochemistry are helpful for the correct diagnosis, which, in turn, is important for two reasons: (i) in relation to prognosis and treatment (adoption of new integrated procedures which seem to promise prolonged survival and increased quality of life); (ii) in relation to medico-legal issues and occupational-related compensation claims following asbestos exposure.