Epithelial appendiceal neoplasms.

The appendiceal malignancies usually arise within a mucocele. The tumor within this structure can be minimally aggressive or of an invasive character. If a low-grade appendiceal malignancy is removed intact, recurrence does not occur. If rupture of the wall of the mucocele occurs with either low-grade or high-grade disease, the epithelial cells within will disseminate to the peritoneal surfaces. Sometimes a second-look surgery must be performed to determine if intraperitoneal spread of mucus and cancer cells has occurred. If the diagnosis of peritoneal dissemination of an appendiceal malignancy has been established, a new treatment with curative intent is indicated. Cytoreductive surgery is combined with perioperative intraperitoneal chemotherapy as a comprehensive management plan. In approximately 900 patients treated at the Washington Cancer Institute, the quantitative prognostic indicators for appendiceal cancer with peritoneal dissemination have been determined. Patients with a complete cytoreduction and low-grade tumor have an 80% survival at 20 years; with high-grade tumors, the survival drops to approximately 45%. The extent of malignancy present within the abdomen by the peritoneal cancer index has a significant impact on survival for both high-grade and low-grade disease. The most important indicator is the completeness of cytoreduction; for both high-grade and low-grade disease, all patients with an incomplete cytoreduction have died by 10 years. The presence versus absence of lymph nodal metastases on survival have minimal significance (P = 0.0495). These results of treatment can be achieved with a 19% incidence of severe complications and a 2% mortality.