The combined modality strategy for PMP may be performed safely with acceptable morbidity and mortality in a specialized unit setting with 63% of patients surviving beyond 10 years. Minimizing nondefinitive operative and systemic chemotherapy treatments before definitive cytoreduction may facilitate the feasibility and improve the outcome of this therapy to achieve long-term survival. Optimal cytoreduction achieves the best outcomes.

Pseudomyxoma peritonei (PMP) is a complex disease with unique biological behavior that usually arises from appendiceal mucinous neoplasia. The classification of PMP and its primary appendiceal neoplasia is contentious, and an international modified Delphi consensus process was instigated to address terminology and definitions. A classification of mucinous appendiceal neoplasia was developed, and it was agreed that "mucinous adenocarcinoma" should be reserved for lesions with infiltrative invasion. The term "low-grade appendiceal mucinous neoplasm" was supported and it was agreed that "cystadenoma" should no longer be recommended. A new term of "high-grade appendiceal mucinous neoplasm" was proposed for lesions without infiltrative invasion but with high-grade cytologic atypia. Serrated polyp with or without dysplasia was preferred for tumors with serrated features confined to the mucosa with an intact muscularis mucosae. Consensus was achieved on the pathologic classification of PMP, defined as the intraperitoneal accumulation of mucus due to mucinous neoplasia characterized by the redistribution phenomenon. Three categories of PMP were agreed-low grade, high grade, and high grade with signet ring cells. Acellular mucin should be classified separately. It was agreed that low-grade and high-grade mucinous carcinoma peritonei should be considered synonymous with disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis, respectively. A checklist for the pathologic reporting of PMP and appendiceal mucinous neoplasms was also developed. By adopting the classifications and definitions that were agreed, different centers will be able to use uniform terminology that will allow meaningful comparison of their results.

The combination of complete cytoreductive surgery and perioperative intraperitoneal chemotherapy provides the only chance for long-term survival for selected patients diagnosed with a variety of peritoneal neoplasms, either primary or secondary to digestive or gynecologic malignancy. Hyperthermic intraperitoneal chemotherapy (HIPEC) delivered in the operating room once the cytoreductive surgical procedure is finalized, constitutes the most common form of administration of perioperative intraperitoneal chemotherapy. This may be complemented in some instances with early postoperative intraperitoneal chemotherapy (EPIC). HIPEC combines the pharmacokinetic advantage inherent to the intracavitary delivery of certain cytotoxic drugs, which results in regional dose intensification, with the direct cytotoxic effect of hyperthermia. Hyperthermia exhibits a selective cell-killing effect in malignant cells by itself, potentiates the cytotoxic effect of certain chemotherapy agents and enhances the tissue penetration of the administered drug. The chemotherapeutic agents employed in HIPEC need to have a cell cycle nonspecific mechanism of action and should ideally show a heat-synergistic cytotoxic effect. Delivery of HIPEC requires an apparatus that heats and circulates the chemotherapeutic solution so that a stable temperature is maintained in the peritoneal cavity during the procedure. An open abdomen (Coliseum) or closed abdomen technique may be used, with no significant differences in efficacy proven to date. Specific technical training and a solid knowledge of regional chemotherapy management are required. Concerns about safety of the procedure for operating room personnel are expected but are manageable if universal precautions and standard chemotherapy handling procedures are used. Different HIPEC drug regimens and dosages are currently in use. A tendency for concurrent intravenous chemotherapy administration (bidirectional chemotherapy, so-called "HIPEC plus") has been observed in recent years, with the aim to further enhance the cytotoxic potential of HIPEC. Future trials to ascertain the ideal HIPEC regimen in different diseases and to evaluate the efficacy of new drugs or drug combinations in this context are warranted.

No abstract

Right hemicolectomy does not confer a survival advantage in patients with mucinous appendiceal tumours with peritoneal seeding. These data suggest that right hemicolectomy should be avoided unless metastatic involvement of the appendiceal or distal ileocolic lymph nodes is documented by biopsy, or the resection margin is inadequate.

Peritoneal cystic mesothelioma is a disease in need of careful longitudinal studies in order to better define the clinical course of these patients. This case report along with a literature review suggests caution in the assessment of cystic mesothelioma as a benign process. This patient had a clear malignant transformation of benign cystic mesothelioma to an invasive and potentially lethal process.

These data support that the PSDSS, undertaken before surgery, is capable of defining CRCPC populations who have a statistically defined high or considerably lower likelihood of long-term survival after CRS/HIPEC. The PSDSS can be quite useful in the decision to enter CRCPC patients into, and their stratification within, clinical trials.

These data suggest that MMC might be a better agent for HIPEC delivery than Oxaliplatin in patients with CRCPC, favorable histologies and low burden of disease (PSDSS I/II) undergoing complete cytoreduction. Prospective studies are warranted, which stratify patients by their PSDSS and randomize them to HIPEC with MMC vs. Oxaliplatin.