Malignant peritoneal mesothelioma

The clinical characteristics of malignant peritoneal mesothelioma are not fully known, and it appears as a variable entity with different types of clinical presentation and with a difficult diagnosis.

Fifteen patients with malignant peritoneal mesothelioma were analyzed for asbestos exposure, clinical presentation, thrombocytosis, X-rays and echotomographic findings, peritoneal fluid cytology, surgical investigations, diagnosis in vita, therapy, cause of death, diagnosis time, and survival time.

Asbestos exposure was present in 12 men. Abdominal pain, ascites, abdominal mass, weight loss and fever were the most common presentation symptoms. In 5 patients, the disease presented as a surgical emergency. Assembling the presenting symptoms, malignant peritoneal mesothelioma was subdivided in 3 types: classical (6 cases), surgical (5 cases) and medical (4 cases). Thrombocytosis was present in 11 cases. Peritoneal fluid cytology was positive for neoplastic mesothelial cells in 8 of 10 cases. Laparotomy (5 patients) and laparoscopy (7 cases) were diagnostic in all cases. Diagnosis in vita was malignant peritoneal mesothelioma for 13 patients, peritoneal carcinomatosis for 1, with only 1 autopsy diagnosis. Seven patients were treated with chemotherapy, showing a progression of the disease. Mean symptoms-to-diagnosis time was 122 days (4-410), and mean symptoms-to-survival time was 345 days (45-1510).

Malignant peritoneal mesothelioma is a very unusual disease characterized by a difficult diagnosis, a rapid evolution, a poor response to therapy, and a very high prevalence of thrombocytosis. A new clinical classification into three types (classical, surgical and medical) may be useful for a correct diagnosis. The early diagnosis of malignant peritoneal mesothelioma remains an important open question.