Recommendations in the management of epithelial appendiceal neoplasms and peritoneal dissemination from mucinous tumours (pseudomyxoma peritonei)

Abstract

The epithelial appendiceal neoplasms are uncommon and are usually detected as an unexpected surgical finding. The general surgeon should be aware of the diversity of its clinical manifestations and biological behaviors along with the significance of the surgical treatment on the progression of the illness and the prognosis of the patients. The operative findings and, especially, tumor histology, determine the type of surgery. Intestinal histologic subtype behaves and should be treated similarly to the right colon neoplasms; while mucinous tumors, often discordant between histology and its aggressiveness, can be treated with a simple appendectomy or require complex oncological surgeries. Mucinous tumors are often associated with the presence of mucin or tumor implants in the abdominal cavity, being the clinical syndrome known as pseudomyxoma peritonei (PMP). PMP tends to present an indolent but deadly evolution and requires a multimodal approach as a single treatment with curative potential: complete cytoreductive surgery plus hyperthermic Intra-peritoneal chemotherapy (CCRS + HIPEC) now considered the standard of care in this pathology. The general surgeon should be aware of the governing principles of the treatment of appendiceal neoplasms with or without peritoneal dissemination, know the therapeutic frontiers in every situation (avoiding unnecessary or counterproductive surgeries) and sending early these patients to specialised centres in the radical management of malignant diseases of the peritoneum in the conditions and with the necessary information to facilitate a possible radical treatment.

Prophylactic hyperthermic intraperitoneal chemotherapy in patients with epithelial appendiceal neoplasms

“…Currently, there is not enough evidence to support the use of systemic chemotherapy in cases of perforated/localised epithelial appendiceal neoplasms, although a recent large study by Asare et al [26] has shown that adjuvant chemotherapy improved overall survival in patients with localised appendiceal adenocarcinoma (stage I to III) for both mucinous and non-mucinous histologies; interestingly, patients with well-differentiated mucinous metastatic appendiceal adenocarcinomas derived no survival benefit from systemic chemotherapy. Other studies have reported that systemic chemotherapy may benefit patients with unresectable or metastatic high-grade disease [27]. There is no clinical evidence justifying the use of systemic chemotherapy for LAMN [27].…”

“…Other studies have reported that systemic chemotherapy may benefit patients with unresectable or metastatic high-grade disease [27]. There is no clinical evidence justifying the use of systemic chemotherapy for LAMN [27].…”

Mucinous appendiceal neoplasms with or without pseudomyxoma peritonei: a review

“…If no tumour cells are detected in the mucinous deposits (acellular mucin), the risk of developing PMP is about 4%. 8 In contrast, when tumour cells are detected in periappendicular mucinous deposits (cellular mucin), 40% of patients will progress to PMP without further treatment. 9 High-grade appendiceal mucinous neoplasms (HAMNs) are rare and still poorly understood.…”

“…16 The aggressiveness of surgeries performed before CRS + HIPEC is an independent negative prognostic factor of survival and adverse events. 8 If mucinous deposits isolated in the right lower quadrant are identified after a thorough exploration or if mucocele rupture occurs intraoperatively, mucin should be completely aspirated or resected for cytologic examination and decision making. As previously stated, acellular mucin is associated with low incidence of peritoneal recurrence and patients can be observed clinically.…”

“…In case of symptomatic bowel obstruction, limiting unnecessary dissection and performing minimal surgery like a bypass or a stoma will prevent further tumour spreading to the retroperitoneum and pelvis, increasing the chance of successful CRS (cytoreductive surgery) + HIPEC (hyperthermic intraperitoneal chemotherapy) 16 . The aggressiveness of surgeries performed before CRS + HIPEC is an independent negative prognostic factor of survival and adverse events 8 . If mucinous deposits isolated in the right lower quadrant are identified after a thorough exploration or if mucocele rupture occurs intraoperatively, mucin should be completely aspirated or resected for cytologic examination and decision making.…”