Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei of Appendiceal Origin: A Single Center Experience.

Background: Pseudomyxoma peritonei (PMP) originating from appendiceal mucinous neoplasm is a rare peritoneal malignancy characterized by the progressive intraperitoneal accumulation of mucus leading to death if left untreated. In recent years, cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) offered increased survival rates. This study aims to identify the clinical, pathological, and surgical features influencing safety and survival outcomes of patients undergoing CRS and HIPEC for PMP of appendiceal origin. Methods: A retrospective analysis of all patients undergoing CRS and HIPEC for PMP of appendiceal origin from January 2015 to May 2019 was conducted at our institution. Results: Study population included 50 patients (74% female, 26% male). The median age at CRS was 60 (38-84). The median peritoneal cancer index (PCI) was 17. Complete cytoreductive surgery (CC 0-1) was achieved in 47 patients (94%). HIPEC chemotherapeutic regimen was based on oxaliplatin for 13 (28%) patients and mitomycin for 34 (72%) patients. We experienced a total of 19 (38%) postoperative complications, of which 14 (74%) of grade I-II and 5 (26%) of grade III-IV, according to the Clavien-Dindo classification. The median follow-up period was 27 months (12-107) from the date of cytoreductive surgery. The mean survival rate was 100 months, with a 5-year OS of 91%. The mean progression-free survival rate was 77 months (0-107), with a 5-year PFS of 63%. Multivariate analysis identified adenocarcinoma histotype and incomplete cytoreduction to significantly worsen progression-free survival, while incomplete cytoreduction was the only independent predictor of poorer overall survival. Conclusion: Complete cytoreduction and appendiceal neoplasm histotype play a crucial role in the survival of patients affected by PMP of appendiceal origin. The rates of morbidity associated with CRS and HIPEC for PMP are acceptable.

Adenocarcinoma of the appendix with extra-appendicular spread: Clinico-surgical and histologic analysis of 27 cases. / Adenocarcinoma de apéndice con extensión extraapendicular: Análisis clínico-quirúrgico e histológico de 27 casos.

BACKGROUND AND OBJECTIVES: Appendiceal neoplasms with extra-appendiceal spread may show different clinical patterns with pseudomyxoma peritonei (PMP) being one of them. We analyse the results in a series of patients treated in our centre. MATERIAL AND METHODS: Retrospective study of patients operated on for appendiceal peritoneal carcinomatosis from January 2012 to May 2015. RESULTS: Twenty-seven consecutive patients were included. Median age 63 years (26-73); 14 were men. Peritoneal carcinomatosis index=16±8 (3-31). The suspected preoperative origins were appendix in 23, ovary in 3 and urothelial in one. Postoperative mortality in 2 patients (7.4%). The remaining 36% presented morbidity. Major morbidity (Clavien-Dindo grades 3 and 4) occurred in 3 patients (12%). CONCLUSIONS: Mucinous adenocarcinomas with extra-appendiceal spread may present as PMP with mucinous ascites, jelly-nodular carcinomatosis without ascites, nodular or desmoplasic plates carcinomatosis without jelly mass/nodules. Histology is not correlated to clinical picture. Preoperative diagnosis of mucinous ovarian cancer in peritoneal carcinomatosis scenario may increase the doubt of their ovarian origin and force an appendiceal origin to be ruled out.

Acute appendicitis, inflammatory appendiceal mass and the risk of a hidden malignant tumor: a systematic review of the literature.

INTRODUCTION: Acute appendicitis is significantly common. Despite the increased use of computed tomography, the number of perforated cases has been stable in the past three decades. Between 2% and 6% of patients with acute appendicitis present appendiceal mass, often described as inflammatory phlegmon or abscess. Malignant tumors are confirmed by pathological analysis in 0.9-1.4% of all appendectomies performed to treat acute appendicitis. However, recent series demonstrate an elevated incidence of malignancies, ranging from 5.9 to 12%, in patients with inflammatory appendiceal mass. METHODS: The analysis was based on a systematic review of the literature. The articles were searched in PubMed for the period from 1987 to 2016. Articles presenting the incidence of the hidden malignancy among patients with appendiceal inflammatory mass were selected. Variables as age, interval appendectomy rate, the incidence of neoplasm, time to surgery, minimally invasive assessment, histology, right colectomy rate and morbidity were analyzed. RESULTS: A total of 13.244 patients were described as presenting acute appendicitis. Appendiceal tumor is present in approximately 1% of the appendectomies, while the rate of neoplasm varies from 10 to 29% in patients presenting appendiceal inflammatory mass. Interval appendectomies, despite been the minority of the procedures, disregard the higher morbidity associated with right sided colectomies. The review of literature also describes oncologic, histologic and clinical aspects of patients presenting appendiceal neoplasm, describing the most frequent histologic subtypes of this illness. CONCLUSION: Hidden appendiceal neoplasm in acute appendicitis are rare, fortunately. However, its incidence is much higher in patients presenting appendiceal inflammatory mass. Hence, interval appendectomy should be considered in this subgroup of patients.