Cancer Diagnosis How Peritoneal Washing Works and What to Know About Its Limits and Risks By Cathy Nelson Updated on January 07, 2025 Medically reviewed by Doru Paul, MD Print Table of Contents View All Table of Contents Uses Limitations How It Works Who Does It How to Prepare Results Risks and Contraindications Peritoneal washing (abdominopelvic washing) is a procedure used to diagnose whether certain types of cancer are present in the peritoneal cavity—the space between the membranes that line the abdomen. It is not performed on its own but during surgeries to remove tumors or see if tumors are present in the body. Peritoneal washing is most commonly performed during ovarian cancer surgeries but is also used in endometrial, pancreatic, and gastric cancer surgeries. The results of this procedure help diagnose a patient with cancer, determine how far the cancer has progressed, and develop a treatment plan. wera Rodsawang / Getty Images Where is the peritoneal area? The peritoneum is a thin membrane that lines the abdominal cavity. It protects and supports organs in the abdomen and pelvis, including the stomach, intestines, and liver. The peritoneum is made of two layers, and the peritoneal cavity is the space between these two layers. The peritoneal cavity doesn’t contain organs but contains small amounts of fluid. Uses Peritoneal washings are typically performed when healthcare providers suspect cancer may be present. It is most commonly used during ovarian cancer surgery. The results from peritoneal washing can determine the type of ovarian tumor a patient has and are part of the guidelines practitioners use when diagnosing the stage of cancer. A cancer's stage indicates how large the tumor is and if the cancer has spread in the body. Peritoneal washing can also help determine the prognosis for certain gastric and pancreatic cancers. In some cases, peritoneal washing is used during "second-look surgery." This surgery is performed once cancer is diagnosed to see how far it has spread or after treatment to see if any cancer cells remain. What is peritoneal washings? Peritoneal washing is a process that involves flushing the peritoneal cavity with a saline solution, which is then drained and analyzed to detect the presence of cancer cells. Limitations Results from specimens obtained during peritoneal washing can sometimes be challenging to interpret. Certain conditions, such as endometriosis, can make cells appear cancerous even though they are benign (not cancerous). Chemotherapy or radiation therapy can also cause cells to appear cancerous even if they are not. The use of peritoneal washing for determining the prognosis and treatment for endometrial cancer, especially in its early stages, is debated in the medical community. How It Works Peritoneal washing is performed during surgery to look for cancer or remove tumors. It is performed with the patient under general anesthesia in a hospital setting and before other surgical procedures. This is to make sure the sample is kept clean and away from any other tumors that might be found or removed during the surgery. The peritoneal cavity is bathed in a sterile saline or saltwater solution during the procedure. The solution and cells from the cavity are then removed and sent to a lab to be tested. How long the procedure will take and the amount of time needed to recover depends on the type and extent of the overall surgery being done. Cancer Surgery Approaches There are different approaches to cancer surgery. They include the following: Open surgery involves a long incision and a longer time to heal than other types. Laparoscopic surgery uses small incisions to place surgical instruments and a camera. The surgeon performs the procedure using video. This method usually has faster healing than open surgery. Robotic-assisted surgery uses small instruments guided by a surgeon controlling a robotic device. This approach also has faster healing than open surgery. Who Does It Peritoneal washing is performed by a surgical team that typically includes oncologists and/or surgical oncologists and an anesthesiologist (a doctor trained to administer anesthesia). How to Prepare There aren't specific steps to take to help you physically prepare for peritoneal washing, but you might want to take some time to mentally prepare for the results you'll receive. You should discuss the outcomes and options with your oncologist or healthcare provider. Results After the procedure, the solution is analyzed for cancer cells (peritoneal cytology). If the peritoneal cytology is positive, then cancer cells are present. If it is negative, that means cancer cells have not been found. The results also typically contain more detailed information about the types of cells found. Once the lab results are in, your healthcare provider will discuss them with you and any other surgical findings and treatments that may be required. What Is Cytology? Cytology means examining a single cell type. Cytology is primarily used to diagnose cancer and is used for Pap smears, screening for fetal abnormalities, or diagnosing infections. Cells are gathered for cytology by collecting bodily fluids, scraping or brushing the surface of a tissue, or removing them with a fine needle. Risks and Contraindications Peritoneal washing does not cause any side effects. However, it is done under general anesthesia during cancer surgery, so you should discuss your risks with your healthcare provider. These risks will vary depending on your health and the type of surgery you have. You also may have side effects from general anesthesia. These side effects are temporary and should begin to subside within 24 hours. They include: NauseaSleepinessDizzinessSore throat (from the breathing tube placed during surgery)Chills Summary Peritoneal washing is performed during surgery for certain types of cancer to help determine if cancer is present or has spread to the peritoneal cavity. It is most commonly performed as part of ovarian cancer surgery but can also be done during surgeries for endometrial, prostate, and gastric cancers. During the procedure, the peritoneal cavity is washed with a sterile solution. The solution and cells are removed and examined for cancer. The results help healthcare providers diagnose cancer, determine the stage of cancer, and develop treatment plans. 12 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Rodriguez EF, Monaco SE, Khalbuss W, Austin RM, Pantanowitz L. Abdominopelvic washings: A comprehensive review. Cytojournal. 2013;10:7. doi:10.4103/1742-6413.111080 Pannu HK, Oliphant M. The subperitoneal space and peritoneal cavity: basic concepts. Abdom Imaging. 2015;40(7):2710-2722. doi:10.1007/s00261-015-0429-5 Zuna RE. Diagnostic cytopathology of peritoneal washings. CytoJournal 2022;19:9. doi:10.25259/CMAS_02_07_2021 Naz, S., Hashmi, A.A., Ali, R. et al. Role of peritoneal washing cytology in ovarian malignancies: correlation with histopathological parameters. World J Surg Onc 13, 315 (2015). doi:10.1186/s12957-015-0732-1 De Andrade JP, Mezhir JJ. The critical role of peritoneal cytology in the staging of gastric cancer: an evidence-based review. J Surg Oncol. 2014;110(3):291-297. doi:10.1002/jso.23632 Blok F, Roes EM, van Leenders GJLH, van Beekhuizen HJ. The lack of clinical value of peritoneal washing cytology in high risk patients undergoing risk-reducing salpingo-oophorectomy: a retrospective study and review. BMC Cancer. 2016;16(1):18. doi:10.1186/s12885-015-2011-5 National Cancer Institute. Peritoneal Washing Lili Wang, Lei Li, Ming Wu, Jinghe Lang, The prognostic role of peritoneal cytology in stage IA endometrial endometrioid carcinomas. Current Problems in Cancer. 2020;44(2):100514. doi:10.1016/j.currproblcancer.2019.100514 Cancer Treatment Centers of America. Peritoneal washing. City of Hope. Peritoneal washing John Hopkins Medicine. Cytology. Johns Hopkins Medicine. Anesthesia options, risks, and side effects. By Cathy Nelson Nelson is a freelance writer specializing in health, wellness, and fitness for more than two decades. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Helpful Report an Error Other Submit