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Imaging Recommendations for Diagnosis, Staging, and Management of Peritoneal Malignancies
CC BY 4.0 · Indian J Med Paediatr Oncol 2023; 44(02): 251-256
DOI: DOI: 10.1055/s-0043-1761165
Abstract
Peritoneum is a serosal membrane lining the solid viscera and the hollow viscus of the abdomen and is made of a single layer of mesothelial cells. The most common primaries that spread to the peritoneum include gastrointestinal, ovarian, colorectal, and peritoneal metastases can be seen at some point during the disease course in 15 to 43%, 60 to 70% and 15 to 20% of patients, respectively. Other malignancies involving the peritoneum such as primary peritoneal carcinoma, peritoneal mesothelioma, peritoneal lymphomatosis, pseudomyxoma peritonei from low-grade appendiceal mucinous neoplasm, are far less common. The review strives to provide a framework for diagnosis and management of the disease.
Authors' Contributions
The manuscript has been read and approved by all the authors, that the requirements for authorship have been met, and that each author believes that the manuscript represents honest work. All authors have contributed equally towards concept, design, definition of intellectual content, literature search, clinical studies, experimental studies, data acquisition, manuscript preparation, manuscript editing and manuscript review.
Publication History
Article published online:
04 May 2023
© 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)
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Abstract
Peritoneum is a serosal membrane lining the solid viscera and the hollow viscus of the abdomen and is made of a single layer of mesothelial cells. The most common primaries that spread to the peritoneum include gastrointestinal, ovarian, colorectal, and peritoneal metastases can be seen at some point during the disease course in 15 to 43%, 60 to 70% and 15 to 20% of patients, respectively. Other malignancies involving the peritoneum such as primary peritoneal carcinoma, peritoneal mesothelioma, peritoneal lymphomatosis, pseudomyxoma peritonei from low-grade appendiceal mucinous neoplasm, are far less common. The review strives to provide a framework for diagnosis and management of the disease.
Introduction
Peritoneum is a serosal membrane lining the solid viscera and the hollow viscus of the abdomen and is made of a single layer of mesothelial cells. Due to low sensitivity of imaging modalities to detected small peritoneal metastasis, the incidence of peritoneal malignancies remains unclear. Peritoneal carcinomatosis is the most common peritoneal surface malignancy and its incidence among the Czech population was 99 per 1,000,000. Primary peritoneal surface malignancies are very uncommon with an incidence of 4.36 per 1,000,000.[1] The most common primaries that spread to the peritoneum include gastrointestinal, ovarian, colorectal, and peritoneal metastases can be seen at some point during the disease course in 15–43%, 60–70%, and 15–20% of patients, respectively.[2] Other malignancies involving the peritoneum such as primary peritoneal carcinoma, peritoneal mesothelioma, peritoneal lymphomatosis, pseudomyxoma peritonei from low grade appendiceal mucinous neoplasm are far less common.
Advanced stage of the primary tumor predisposes to peritoneal carcinomatosis. Apart from T- and N-stage, positive peritoneal fluid cytology and histological subtype of the primary are risk factors for peritoneal metastases. The most common symptoms of peritoneal surface malignancies include abdominal pain, abdominal distension from ascites or bowel obstruction. Non-specific symptoms include nausea, vomiting, fatigue, weight loss, and constipation. Tumor markers are used for diagnosis, prognosis, and for assessing treatment response. Carcinoembryonic antigen (CEA) and CA-19-9 are used in gastrointestinal malignancies. CA-125 is used for ovarian cancer and mesothelioma. CA-125 and CA72-4 are used for gastric cancer.
Risk Factors and Etiopathogenesis[2]
Advanced stage of the primary tumor, regional lymph node involvement, histological subtype and positive peritoneal cytology, are the usual risk factors for the development of peritoneal metastases from underlying primary neoplasm.
Loss of E-cadherin, a cell–cell adhesion molecule, is responsible for the detachment of cancer cells from the primary tumor. Rapid cellular proliferation, defective lymphatic drainage, fibrosis, and contraction of the interstitial matrix, and increased osmotic pressure generated by anerobic glycolysis and leakage of plasma proteins, result in the shading of cells, due to elevated interstitial fluid pressure. Cutting of tumor or sectioning of the vascular, lymphatic, or biliary drainage is also responsible for peritoneal seeding.
The peritoneal deposits tend to gravitate in the cul-de-sac and the right paracolic gutters. Other locations include the subdiaphragmatic area and the mesentery, owing to diaphragmatic excursions.
Clinical/Diagnostic Workup
Clinically, the patient can present with signs and symptoms of primary malignancy.
Clinical features of peritoneal involvement are abdominal distention and pain. Patient can also have non-specific presentations such as fatigue, nausea, anorexia, weight loss, and constipation.
Serum tumor markers can be used for diagnosis, prognosis, and response assessment of peritoneal malignancy. The common tumors markers are CA 19-9 for pancreatobiliary system, CEA for GI tract, and CA 125 for ovarian primaries and mesothelioma. Cell block preparation, immunohistochemistry with appropriate markers indicate the possible primary, if not evident at presentation.
Surgical exploration using laparoscopy is the most sensitive modality for evaluation of the extent of the disease and assessment of its potential surgical resectability. Diagnostic laparoscopy is essential for the assessment of peritoneal cancer index (PCI).
Imaging Referral Guidelines:
Ultrasound findings might raise the suspicion of an underlying peritoneal malignancy and act as a trigger for cross-sectional imaging. However, ultrasound is not recommended as a sole imaging modality for staging peritoneal surface malignancy.
Ultrasound is useful for image-guided biopsy of peritoneal or omental disease.
CECT of the thorax, abdomen, and pelvis is the recommended imaging modality for initial assessment of patients with peritoneal malignancy.
Administration of both intravenous and positive oral contrast are recommended as a part of an optimal CT protocol.
MRI is not recommended for all patients with peritoneal surface malignancy. Contrast-enhanced MRI with diffusion-weighted imaging may have a role in select patients with low-volume peritoneal disease on CECT and incomplete diagnostic laparoscopy due to adhesions.[3]
PET-CT is not recommended for initial assessment of peritoneal malignancy.
Imaging Guidelines
a) Screening and diagnosis
Peritoneal surface malignancy is often suspected based on incidentally detected ultrasound findings such as ascites, omental, or peritoneal thickening. However, confirmation of diagnosis is with histopathology either using ultrasound-guided biopsy or by diagnostic laparoscopy and biopsy.
b) Staging
CECT of the thorax, abdomen, and pelvis is the imaging modality of choice for staging peritoneal surface malignancy. Studies done on new-generation CT scanners with thin section imaging and multiplanar reconstructions have improved sensitivity of 88 to 93% for detecting peritoneal disease. However, sensitivity to detect disease smaller than 1 cm and for detecting small bowel and mesenteric disease remain poor. Staging system used for primary peritoneal surface malignancy is the same as ovarian cancer and fallopian tube malignancies. Peritoneal cancer index (PCI) provides a comprehensive estimate of tumor volume within the peritoneal cavity. Imaging underestimates PCI. Despite these limitations, CECT is an effective modality for obtaining a general overview of the disease extent and exclude those who may not benefit from cytoreductive surgery and HIPEC.[4]
Radiology reports must mention the following[5]:
P – radiological estimation of PCI (rPCI), local extent of the primary malignancy in patients with peritoneal carcinomatosis.
A – presence or absence of ascites and abdominal wall disease
U – presence of disease in unfavorable sites, which make complete cytoreduction unlikely or difficult.
S – small bowel and mesenteric disease
E – presence of extraperitoneal metastases or lymph nodes.
Peritoneal Cancer Index
Peritoneal cancer index (PCI) is a measure of the peritoneal disease burden and distribution, introduced by Jacquet and Sugarbacker.[6] The abdomen is divided into 13 regions ([Table 1])[7] and a score is assigned depending on the disease burden in each region, resulting in minimal score of 0 to maximum score of 39. PCI is best assessed at laparoscopy and/or laparotomy. Preoperative assessment of PCI by MDCT can arm the surgeon with surgical roadmap and act as an arbitrator for decision regarding cytoreductive surgery[8]
|
Region |
Score |
Scoring |
Size |
|
|---|---|---|---|---|
|
0 |
Central |
LS0 |
No visible tumor |
|
|
1 |
Right upper |
|||
|
2 |
Epigastrium |
|||
|
3 |
Left upper |
LS1 |
< 0> |
|
|
4 |
Left flank |
|||
|
5 |
Left lower |
|||
|
6 |
Pelvis |
LS2 |
0.5 cm–5.0 cm |
|
|
7 |
Right lower |
|||
|
8 |
Right flank |
|||
|
9 |
Upper jejunum |
LS3 |
> 5cm or caking |
|
|
10 |
Lower jejunum |
|||
|
11 |
Upper ileum |
|||
|
12 |
Lower ileum |
|||
|
Total |
||||
- Klos D, Riško J, Loveček M. et al. Trends in peritoneal surface malignancies: evidence from a Czech nationwide population-based study. World J Surg Oncol 2019; 17 (01) 182 DOI: 10.1186/S12957-019-1731-4.
- Cortés-Guiral D, Hübner M, Alyami M. et al. Primary and metastatic peritoneal surface malignancies. Nat Rev Dis Primers 2021; 7 (01) 91 https://doi.org/10.1038/s41572-021-00326-6
- Chandramohan A, Shah N, Thrower A. et al. Communicating imaging findings in peritoneal mesothelioma: the impact of ‘PAUSE’ on surgical decision-making. Insights Imaging 2021; 12 (01) 174 DOI: 10.1186/S13244-021-01118-Y.
- Chandramohan A, Thrower A. A practical guide to peritoneal malignancy. In: Cecil T, Bunni J, Mehta A, eds. The PMI Manual. CRC Press; 2019
- Chandramohan A, Thrower A, Smith SA, Shah N, Moran B. “PAUSE”: a method for communicating radiological extent of peritoneal malignancy. Clin Radiol 2017; 72 (11) 972-980 DOI: 10.1016/J.CRAD.2017.07.005.
- Jacquet P, Sugarbaker PH. Clinical research methodologies in diagnosis and staging of patients with peritoneal carcinomatosis. Cancer Treat Res 1996; 82: 359-374 DOI: 10.1007/978-1-4613-1247-5_23.
- Aherne EA, Fenlon HM, Shields CJ, Mulsow JJ, Cronin CG. What the radiologist should know about treatment of peritoneal malignancy. Am J Roentgenol 2017; 208 (03) 531-543 https://doi.org/10.2214/AJR.16.16646
- Panagiotopoulou PB, Courcoutsakis N, Tentes A, Prassopoulos P. CT imaging of peritoneal carcinomatosis with surgical correlation: a pictorial review. Insights Imaging 2021; 12 (01) 168 DOI: 10.1186/S13244-021-01110-6/FIGURES/16.
References
- Klos D, Riško J, Loveček M. et al. Trends in peritoneal surface malignancies: evidence from a Czech nationwide population-based study. World J Surg Oncol 2019; 17 (01) 182 DOI: 10.1186/S12957-019-1731-4.
- Cortés-Guiral D, Hübner M, Alyami M. et al. Primary and metastatic peritoneal surface malignancies. Nat Rev Dis Primers 2021; 7 (01) 91 https://doi.org/10.1038/s41572-021-00326-6
- Chandramohan A, Shah N, Thrower A. et al. Communicating imaging findings in peritoneal mesothelioma: the impact of ‘PAUSE’ on surgical decision-making. Insights Imaging 2021; 12 (01) 174 DOI: 10.1186/S13244-021-01118-Y.
- Chandramohan A, Thrower A. A practical guide to peritoneal malignancy. In: Cecil T, Bunni J, Mehta A, eds. The PMI Manual. CRC Press; 2019
- Chandramohan A, Thrower A, Smith SA, Shah N, Moran B. “PAUSE”: a method for communicating radiological extent of peritoneal malignancy. Clin Radiol 2017; 72 (11) 972-980 DOI: 10.1016/J.CRAD.2017.07.005.
- Jacquet P, Sugarbaker PH. Clinical research methodologies in diagnosis and staging of patients with peritoneal carcinomatosis. Cancer Treat Res 1996; 82: 359-374 DOI: 10.1007/978-1-4613-1247-5_23.
- Aherne EA, Fenlon HM, Shields CJ, Mulsow JJ, Cronin CG. What the radiologist should know about treatment of peritoneal malignancy. Am J Roentgenol 2017; 208 (03) 531-543 https://doi.org/10.2214/AJR.16.16646
- Panagiotopoulou PB, Courcoutsakis N, Tentes A, Prassopoulos P. CT imaging of peritoneal carcinomatosis with surgical correlation: a pictorial review. Insights Imaging 2021; 12 (01) 168 DOI: 10.1186/S13244-021-01110-6/FIGURES/16.