[Clinical analysis of pseudomyxoma peritonei presenting with external abdominal hernia as the initial symptom]

Objective: To analyze the clinical characteristics and key points of diagnosis and treatment in patients with pseudomyxoma peritonei (PMP) presenting with external abdominal hernia as the initial manifestation. Methods: A descriptive case-series study was conducted. From May 2015 to September 2024, a total of 569 patients diagnosed with PMP and treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS+HIPEC) were admitted to Beijing Shijitan Hospital. Among them, 13 patients (2.3%) presented with external abdominal hernia as the initial clinical manifestation. Clinical data of these 13 patients were retrospectively analyzed, including the type of inguinal hernia, pathological diagnosis, peritoneal cancer index (PCI), interval from pathological diagnosis to first CRS+HIPEC, completeness of cytoreduction (CC) score, operation duration, and serious adverse events within 30 postoperative days and prognosis. Results: The median age of the 13 patients was 51 years (range 33-71 years), including 10 males. Twelve patients presented with inguinal hernia as the initial symptom: 6 with right inguinal hernia, 5 with left inguinal hernia, and 1 with bilateral inguinal hernia. The remaining 1 patient had an umbilical hernia. The hernia contents were tumor tissue and mucus in 11 patients, while 2 patients had complete spontaneous reduction of hernia contents. Pathological diagnosis showed low-grade in 10 cases, acellular mucus, high-grade, and high-grade with signet-ring cells in 1 case each. The median interval from pathological diagnosis to first standard CRS+HIPEC was 2.5 (range 0.6-11.6) months . Perioperative assessment showed that 7 patients had PCI < 20, 9 patients had CC score 0-1, median ascites volume was 800 (range 0-20 000) ml, median Karnofsky performance status score was 90 (range 80-100), and median operation duration was 655 (range 403-1018) minutes . Seven patients developed postoperative serious adverse events: 4 involving the respiratory system, 1 the circulatory system, 1 the digestive system, and 1 with infection. No deaths occurred within 30 postoperative days. The median follow-up was 61.2 months (95%CI: 36.3-86.1), the mean overall survival was 124.3 months (95%CI: 92.1-156.6), and 2 patients died. Conclusions: In PMP patients presenting with external abdominal hernia as the initial symptom, inguinal hernia is the most common type, and most hernia contents cannot be reduced spontaneously. If PMP is suspected during surgery for external abdominal hernia, prompt referral to a specialized peritoneal metastasis center for CRS+HIPEC is recommended.