Malignant peritoneal mesothelioma: a multicenter study on 81 cases.

Background: Malignant peritoneal mesothelioma (MPM) is a rare disease characterized by a difficult diagnosis, different types of presentation, variable course and poor prognosis.
Materials and Methods: Eighty-one patients with MPM observed in 14 Italian oncology institutions from 1982 to 2007 have been examined with the aim of delineating the history of MPM.
Results: Presentation symptoms were ascites, abdominal pain, asthenia, weight loss, anorexia, abdominal mass, fever, diarrhea and vomiting in various associations. Computed tomography scan and echotomography signs were ascites, abdominal mass and peritoneal thickening. Peritoneal fluid cytology (61 cases) was positive for mesothelioma in 31 and for malignancy, not mesothelioma, in 13. Laparoscopy was carried out in 40 cases and laparotomy in 36. Thrombocytosis was present in 59 cases. Associated tumors diagnosed during the lifetime were colorectal cancer in two cases and cheek carcinoma, thyroid carcinoma, tongue carcinoma, bladder carcinoma and testicular seminoma. Thirty patients were treated with surgery and 45 with chemotherapy. The median survival time from diagnosis is 13 months. Ascites, fever and vomiting were significative variables at presentation; only vomiting holds significance in a multivariate analysis.
Conclusions: MPM is a disease with various types of presentation, frequently associated with thrombocytosis, sometimes with other tumors. Survival and diagnosis time can differ in various types of MPM. Prognosis is poor.