Peritoneal mesothelioma is an uncommon primary tumour of the peritoneal lining. It shares epidemiological and pathological features with, but is less common than its pleural counterpart, which is described in detail in the general article on mesothelioma. Other sub-types (also discussed separately) include :
Approximately 20 - 30% of all mesotheliomas arise from the peritoneal serosal lining. As with pleural mesothelioma, there is also a strong association with asbestos exposure, and this occupational hazard probably accounts for disease predominance in middle aged to older males (may also account for the slightly increased male predilection). Despite this, approximately 50% of cases have no history of exposure to asbestos.
The overall incidence is at approximately 1 - 2 cases / million.
Typically patients present with weight loss, abdominal pain and/or abdominal distension.
There is a reported correlation between the clinical presentation and CT findings, with subgrouping into 2:
- “dry-painful” type : presenting with abdominal pain, CT features of peritoneal mass(es) and little to no ascites;
- “wet” type : presenting with abdominal distension, CT findings of ascites and widespread nodules without a predominant mass and
- "mixed" type with both pain and ascites present
As with pleural mesothelioma, three histologic sub-types exist :
- sarcomatoid and
- biphasic (mixed epithelial-sarcomatoid)
- presence of calcified pleural plaques, indicative of asbestos exposure
- in contrast, peritoneal tumoral calcification is uncommon
- nodular, irregular peritoneal and omental thickening, progressing to omental caking
- peritoneal or omental masses
- variable ascites (mild to moderate)
- direct invasion of abdominal viscera, especially liver and colon.
- concurrent pleural involvement is not uncommon on CT at diagnosis 7
Peritoneal mesothelioma does not tend to spread to distant organs and lymphadenopathy is usually not a feature.
- variable sonographic appearances, from sheet-like hypoechoic to echogenic masses1,4
- omental thickening
Gallium scan : diffuse uptake throughout the peritoneal cavity 4
Peritoneal masses and nodules demonstrate1:
- T1 : low-intermediate signal
- T2 : high signal
- C+ (Gd) : shows enhancement
Treatment and prognosis
Treatment options include cytoreductive surgery, peritonectomy and introperitoneal chemotherapy. However the prognosis is very poor, with death usually within one year 6.
General considerations include
peritoneal carcinomatosis :
- most common cause of omental nodules/caking
- more likely to contain dystrophic calcification
- pseudomyxoma peritonei
- lymphoma with peritoneal involvement
- peritoneal involvement with tuberculosis
- mesenteric panniculitis (retractile mesenteritis)
- 1. Federle MP, Jeffrey RB, Woodward PJ et-al. Diagnostic Imaging: Abdomen, Published by Amirsys®. Lippincott Williams & Wilkins. (2009) ISBN:1931884714. Read it at Google Books - Find it at Amazon
- 2. Busch JM, Kruskal JB, Wu B et-al. Best cases from the AFIP. Malignant peritoneal mesothelioma. Radiographics. 22 (6): 1511-5. doi:10.1148/rg.226025125 - Pubmed citation
- 3. Brant WE, Helms CA. Fundamentals of diagnostic radiology. Lippincott Williams & Wilkins. (2007) ISBN:0781761352. Read it at Google Books - Find it at Amazon
- 4. Dach J, Patel N, Patel S et-al. Peritoneal mesothelioma: CT, sonography, and gallium-67 scan. AJR Am J Roentgenol. 1980;135 (3): 614-6. AJR Am J Roentgenol (citation) - Pubmed citation
- 5. Boffetta P. Epidemiology of peritoneal mesothelioma: a review. Ann. Oncol. 2007;18 (6): 985-90. doi:10.1093/annonc/mdl345 - Pubmed citation
- 6. Mohamed F, Sugarbaker PH. Peritoneal mesothelioma. Curr Treat Options Oncol. 2002;3 (5): 375-86. - Pubmed citation
- 7. Whitley NO, Brenner DE, Antman KH et-al. CT of peritoneal mesothelioma: analysis of eight cases. AJR Am J Roentgenol. 1982;138 (3): 531-5. AJR Am J Roentgenol (abstract) - Pubmed citation
- 8. Levy AD, Arnáiz J, Shaw JC et-al. From the archives of the AFIP: primary peritoneal tumors: imaging features with pathologic correlation. Radiographics. 28 (2): 583-607. doi:10.1148/rg.282075175 - Pubmed citation
Synonyms & Alternative Spellings
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