A case report of low-grade appendiceal mucinous neoplasm in perforated appendicitis: literature review, acute surgery and later additional HIPEC treatment to prevent pseudomixoma peritonei

Low-grade appendiceal mucinous neoplasm (LAMN) accounts less than 0.5% of all gastrointestinal neoplasm. Early stage AMNs are usually incidentally diagnosed on a surgical specimen after appendectomy for acute appendicitis. In this study, we reported a 42-year-old female presented complaining right lower abdominal pain for 3 days. Abdominal US revealed inflamed appendix surrounded by ipo-anechoic area of 3 cm, with increased thickness of near ileus. Intraoperatively a fistula between appendix and terminal ileum was found; for that reason, a right hemicolectomy was performed. Histopathology indicated a low-grade appendiceal mucinous neoplasms (LAMNs). Four months later the patient underwent hyperthermic intraperitoneal chemotherapy (HIPEC) with C-mitomycin and Cisplatin and was followed up for 6 months with no disease progression, confirmed by CT scan. At present there is not a consensus about LAMNs treatment, due to the scarcity of cases. Consensus statement of the Peritoneal Surface Oncology Group published in 2020 seems to be the best guideline available nowadays; Recommendations are provided based on three Delphi voting rounds with GRADE-based questions amongst a panel of 80 worldwide PMP experts. Given the rarity of these pathologies, each clinical case and longer follow up are important. Appropriate surgery-based treatment followed by HIPEC could contribute to the improvement of prognosis and severe outcomes among these patients. In our opinion patients affected by LAMN should receive prophylactic HIPEC treatment in order to achieve the greatest survival benefit even if they run the risk of overtreatment.