Peritoneal Cancer and Ascites

April 12, 2023 9:53 AM

If a patient has peritoneal carcinomatosis, would the ascites fluid have malignant cells?

Patient has confirmed colon cancer. Treatment so far has been just a colostomy (no radiation or chemo). Latest PET scan showed what doctors believe is advanced peritoneal carcinomatosis. Patient just had paracentesis. Cytologic diagnosis on the ascites states no malignant cells identified. Also, the CBC showed the patient's white blood cell and RBC count to be in the normal range.

Are these test results consistent with peritoneal carcinomatosis? I would have thought there'd be cancerous cells in the ascites, as well as something going on with blood cell counts.

I have no medical training, I'm just trying to understand the test results. I know this is something that should be discussed with the patient's medical team, but that will wait until the next appointment. (You are not my medical advisor, etc, etc. I'm just asking a general question.)

posted by La Gata to Health & Fitness (1 answer total)

IANYD but as an oncologist, often if someone has peritoneal carcinomatosis, there are malignant cells present in ascites fluid. Having said that, it can sometimes take more than one paracentesis before this can be confirmed. I would not use the CBC as a diagnostic point in this case.

Peritoneal carcinomatosis can also be confirmed with a peritoneal biopsy. I often point people to the NCCN Guidelines for Patients as a good place to start for well-validated, vetted information about cancer treatment. I'm sorry that this is happening... it's a tough one.
posted by honeybee413 at 10:20 AM on April 12, 2023 [6 favorites]