- Clinical examination of abdomen
- Rectal/vaginal exam
- CEA - often raised in pseudomyxoma from the appendix, and in 50% with colorectal cancer
- CA 19-9 - marker for peritoneal involvement
- CA 125 - the levels of CEA and CA-125 (or HE4) should always be measured if ovarian tumor is suspected. Increased CEA for suspected ovarian cancer will in most cases be a metastasis from a primary tumor in the bowel.
- General parameters (renal function, liver function, Hb, white, thrombocytes)
- CT of abdomen/pelvis for possible lymph node-/liver metastasis.
- CT of thorax to exclude lung metastases.
- PET scans have low sensitivity for mucinous tumors, but may be important to exclude central nodal metastases or distant metastases.
There is no non-invasive method to diagnose extensiveness of peritoneal spreading at a relatively early stage. All imaging techniques tend to underestimate the prevalence of disease extensiveness in the abdominal cavity. Examinations with imaging techniques are more effective for inspecting diseases within the organs, and less so for inspecting organs superficially.
- Aspiration of ascites
- Mucinous fluid without cells indicates adenomucinosis.
- Serous fluid with tumor cells indicates peritoneal carcinomatosis.
- Separated cancer cells can provide accurate diagnosis.
- Laporoscopy is the best method to evaluate extent. The laparoscopy findings should describe extensivenss as precisely as possibly, especially in the small intestine. It is helpful the examination can be recorded. The method is of lesser value if there are prominent adherances.
- Biopsy is performed for assessment of malignancy grade.
Other investigations are performed depending on what organs are involved.