Pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is a rare malignancy of the abdomen with an incidence of only 1-2 cases per 1 million inhabitants per year. The most common site of origin of PMP is as a mucinous neoplasm of the appendix and other extra-abdominal or intra-abdominal organs as the primary site are much rarer. Research and analysis of the current literature. The classification into low-grade and high-grade PMP is carried out according to the morphological appearance and growth pattern. Low-grade PMP shows cells with smooth nuclei and mostly acellular mucin, whereas high-grade PMP is characterized by massive atypia of the nuclei partly with signet ring cells and a clearly increased cell architecture in the mucin. Low-grade PMP grows in a displacing manner and high-grade PMP can infiltrate abdominal organs. The cells in PMP show a so-called redistribution phenomenon where cancer cells are distributed within the abdominal cavity and settle in peritoneal folds. Hematogenous metastasis is rare. The most common symptom of PMP is an increase in abdominal girth, followed by an unclear pelvic tumor in women and a newly developed inguinal hernia in men. In 2 out of 10,000 laparotomies PMP is an incidental finding. For the diagnostics ultrasound examination and computer tomography (CT) are most often used. Best practice in diagnostics is laparoscopy during which tissue samples should be collected. The treatment of choice, when possible, is complete cytoreduction with removal of the mucin in combination with an intraperitoneal chemotherapy which can be performed during the operation as hyperthermic intraperitoneal chemotherapy (HIPEC) or afterwards as early postoperative intraperitoneal chemotherapy (EPIC). The intraperitoneal administration of chemotherapy as an aerosol, known as pressurized intraperitoneal aerosol chemotherapy (PIPAC) is at present in the trial stage with results still pending. Other forms of treatment, such as systemic chemotherapy and abdominal irradiation are only used with palliative intent. If complete cytoreduction is achieved the prognosis is good with an average survival time of 16.3 years but the prognosis is poorer if tumor cells remain within the abdomen. If intraperitoneal chemotherapy (HIPEC or EPIC) is administered the overall survival and the progression-free interval are also increased.