Mesothelioma and Miscellaneous Disease Processes

First described over a century ago, malignant peritoneal mesothelioma (MPM) is a rare, aggressive malignancy typically presenting with diffuse peritoneal studding and/or ascites. Although usually advanced disease is found within the peritoneal cavity, spread beyond the abdomen is uncommonly encountered. Although advances in systemic chemotherapy have been made, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have emerged as the mainstay of treatment. Median overall survival of approximately 50 months with CRS/HIPEC has been demonstrated, with age, gender, histologic subtype, peritoneal carcinomatosis index (PCI), comorbidities, nodal and extra-abdominal metastases, and completeness of cytoreduction all playing a role in prognosis. Similarly, urachal-derived peritoneal carcinomatosis, a clinical condition involving extensive spread of intraperitoneal mucin from a urachal primary, is an exceedingly rare disease whose pathophysiologic characteristics have mainly been determined by case series. As there is no standard systemic therapy for urachal carcinomatosis, CRS/HIPEC provides a useful treatment strategy, with a median overall survival approaching 60 months. The completeness of cytoreduction during CRS/HIPEC for urachal-derived carcinomatosis significantly influences prognosis, with increasing PCI trending toward poorer overall survival. For both of these rare diseases, CRS/HIPEC offers durable, long-term survival in appropriately selected patients.