Malignant Peritoneal Mesothelioma: Clinicopathological Characteristics of Two Cases

Introduction. Peritoneal mesothelioma is a rare tumor, presenting difficulties in diagnosis and treatment. Peritoneum is the second most common area of the mesothelioma after pleura, and even synchronous pleural and peritoneal mesotheliomas are observed in 30–45% of all cases. The diagnosis may be difficult due to lack of specific symptoms and clinical findings. In addition, a delay in the diagnosis is not rare especially in the absence of previous asbestos exposure. Here we report two cases of malignant peritoneal mesotheliomas. The diagnostic and therapeutic approaches for these rare neoplasms are discussed. Case Presentation. The cases were two men (one aged 54 years old and the other 40 years old). Prolonged abdominal pain and swelling were the primary presentation symptoms and findings. The mesotheliomas were developed in the right upper quadrant of abdomen in both of the cases. Both cases were treated with surgical resection. Final diagnosis were possible with histological and immunohistochemical documentation of tumor characteristics, which were consistent with dictating a mesothelial origin. No history of asbestos exposure was reported. Conclusion. Peritoneal mesotheliomas are rare clinical entities. However, patients with prolonged abdominal pain and abdominal masses should be considered to have atypical pathologies such as peritoneal mesotheliomas. 1. Introduction Malignant peritoneal mesothelioma is an uncommon disease and has a very poor prognosis with an average survival time between 5 and 12 months [1]. Inadequate and delayed treatment is the main reason for this short survival time. The incidence is about one in a million. Nearly one fifth to one third of all mesotheliomas is localized in the peritoneum. Fifty percent of reported cases have a history of asbestos exposure [1]. The delayed diagnosis of peritoneal mesothelioma is common due to a very long time interval between initial asbestos exposure and the onset of the symptoms. In addition, generally, the presenting symptoms are mild and nonspecific. Here, we report two extremely rare cases of epithelioid malignant mesothelioma and clinical presentation and outcomes have been discussed. 2. Case Presentation Case 1: a 54-year-old male patient was admitted with complaints of shortness of breath simultaneous abdominal pain, stiffness, and swelling. The patient was referred to specialist pulmonologist. Thorax CT scan revealed the presence of common pleural effusion on the right side of the patient and changes in the lung fields adjacent to the effusion revealed the presence of passive