ObjectiveTo summarize experiences of diagnosis and treatment of intraperitoneal mass after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in treatment of hepatocellular carcinoma (HCC).MethodThe clinicopathologic data of a 40 years old case of HCC with intraperitoneal mass after ALPPS in the First Affiliated Hospital of Guangxi Medical University were retrospectively analyzed.ResultsThe patient was admitted to this hospital because of abdominal pain and abdominal distension for 5 d. The intraperitoneal mass was found and its nature was not clear on year 1 after ALPPS on admission. After discussion of multidisciplinary team (MDT), the exploratory laparotomy and abdominal tumor resection were planned to perform. The intraperitoneal mass and appendix were removed, the resected tissues were diagnosed as chronic inflammation and retroperitoneal abscess caused by perforation of suppurative appendicitis, respectively. The anti-infection and symptomatic support treatment were strengthened to perform after operation, the patient discharged after recovery. The patient was followed up so far, the general condition was good, and there was no clinical recurrence.ConclusionsFor patient underwent ALPPS, regular follow-up should be paid attention to. If intraperitoneal mass is found and nature is not clear, MDT discussion should be performed so as to make a more reasonable treatment plan. After exclusion of contraindications, surgical treatment should be carried out to furthest benefit patients.