Peritoneal Cancer

The infiltration of malignant cells into the serous membrane that lines the abdominal cavity, viscera, and coelom in amniotes is termed peritoneal surface malignancy or peritoneal cancer. This condition is categorized into primary and secondary types. Primary mesothelioma arises from the de novo development of cancer in the mesothelium of the abdomen. In contrast, secondary peritoneal cancer occurs due to the spread of tumor cells from other locations into the peritoneal cavity. Primary peritoneal cancer is further classified based on histology, with terms such as extraovarian primary peritoneal carcinoma (EOPPC), serous surface papillary carcinoma, papillary serous carcinoma of the peritoneum, extraovarian Mullerian adenocarcinoma, and normal-sized ovarian carcinoma syndrome being used to describe this type.  Additional types of peritoneal cancer include malignant peritoneal mesothelioma, multicystic mesothelioma, leiomyosarcomas, leiomyomatosis peritonealis disseminata, and desmoplastic small round cell tumor. Swerdlow initially reported EOPPC as "mesothelioma of pelvic peritoneum" in a case study published in 1959. EOPPC behaves similarly to serous ovarian cancer, often with minimal involvement of the ovaries. While these types exhibit varied histological features, they share similarities in presentation, diagnostic evaluation, and treatment approaches (see  Light Microscopic Features of Types of Peritoneal Cancer). Secondary or metastatic peritoneal carcinomatosis commonly originates from primitive malignancies affecting gastrointestinal and gynecological structures. Metastasis may occur through transcoelomic, vascular, or lymphatic routes, with the first description dating back to 1931, illustrating the local spread of ovarian cancer.  Primary peritoneal cancer is typically classified as stage III or IV, while metastasis is categorized as stage IV. The nonspecific clinical presentation often results in delayed diagnosis, decreasing survival rates. Surgical resection and intraperitoneal chemotherapy are considered critical approaches for disease elimination. Nevertheless, advancements in understanding peritoneal physiology and tumor seeding pathways, coupled with technological progress, have facilitated the development of more effective treatment modalities. In the absence of extensive systemic disease, achieving locoregional control of the cancer holds promise in managing this late-stage condition.