Diagnosis of Peritoneal Carcinomatosis

Initial Diagnostic Approach

The British Journal of Cancer recommends obtaining a history of previous malignancy, as the most common primary origins of peritoneal carcinomatosis are breast, colon, gastric, pancreatic, and ovarian cancer 1, 2
Measure serum tumor markers: CA-125 before any intervention, and consider CA19.9 and CEA if CA-125 is normal, as recommended by the British Journal of Cancer 1, 3
In young women, measure alpha-fetoprotein and beta-HCG to exclude germ cell tumors, as suggested by the British Journal of Cancer 1, 3

The British Journal of Cancer suggests that ultrasound detects peritoneal carcinomatosis with high specificity, identifying omental involvement in 97% of cases, peritoneal implants in 54%, and serosal involvement in 19% 1, 4
The Annals of Oncology recommend CT with contrast of the thorax, abdomen, and pelvis as the second-line imaging method, due to its availability, cost-effectiveness, and relatively high sensitivity 5
The Journal of Clinical Oncology notes that the sensitivity of CT for detecting peritoneal carcinomatosis is low (28-51%), although specificity is high (97-99%) 6, 7

The Annals of Oncology recommend laparoscopic diagnosis with peritoneal cytology as the standard indication for all potentially resectable gastric cancers stage IB-III, and in cases with high risk of peritoneal carcinomatosis not visible or doubtful on CT 5, 8
The Journal of Clinical Oncology states that laparoscopy has a sensitivity of 85% and specificity of 100% for detecting peritoneal carcinomatosis not identified by imaging, compared to only 3% detection by PET-CT 7, 5
The Annals of Oncology note that the global sensitivity for detecting peritoneal metastases is 84.6% with a specificity of 100% 5

The British Journal of Cancer recommends paracentesis with cytological analysis of ascitic fluid as the initial standard, with a sensitivity of 96.7% if three samples are sent immediately 1, 4, 2
The Hepatology journal suggests that cytology is positive only in the presence of peritoneal carcinomatosis, not in hepatic or lymph node metastases without peritoneal involvement 2
The British Journal of Cancer notes that peritoneal biopsies alone are not sufficient for definitive diagnosis, and require representative samples of good quality and adequate size of the primary tumor when possible 1, 4

The Hepatology journal states that tuberculosis peritoneal requires biopsy of tissue, with a diagnostic yield of 84-100% for caseating granulomas and acid-alcohol resistant bacilli 2, 9

The British Journal of Cancer warns not to rely solely on CT for preoperative staging due to its low sensitivity (28-51%) 4, 6, 7
The Hepatology journal cautions that a negative ascitic fluid cytology does not exclude peritoneal carcinomatosis, especially in low-volume disease 2
The Annals of Oncology emphasize the importance of laparoscopic diagnosis in surgical candidates to detect hidden disease that would change management, especially in T3/T4 tumors and non-cohesive tumors 5
The Journal of Clinical Oncology advises against routine PET-CT due to its limited utility, especially in mucinous or diffuse tumors 7, 5

The National Comprehensive Cancer Network recommends performing a physical examination focusing on ascites, abdominal distention, pelvic masses, and supraclavicular lymphadenopathy in patients with suspected peritoneal carcinomatosis 10

Enhanced abdominal/pelvic CT is specifically recommended for diagnosis of ovarian metastases and peritoneal metastases in colorectal cancer by the Cancer Communications guideline 11
Diffusion-weighted imaging (DWI) improves detection of small peritoneal deposits, as suggested by the Journal of the American College of Radiology 12

The Annals of Oncology guideline recommends diagnostic laparoscopy with peritoneal cytology as the standard indication for all potentially resectable stage IB-III gastric cancers and high-risk cases where CT is doubtful 13
The Peritoneal Cancer Index (PCI) should be used to quantify disease burden, with lower PCI scores associated with better prognosis, according to the Annals of Oncology 13

The Journal of the National Comprehensive Cancer Network : JNCCN recommends ruling out bowel, uterine, pancreatic cancers and lymphoma in women with pelvic masses 10

The Annals of Oncology guideline advises against relying solely on CT for preoperative staging due to its low sensitivity and significant underestimation of peritoneal disease burden 13
The Annals of Oncology also recommends avoiding routine PET-CT due to limited utility, particularly in mucinous or diffuse tumors 13