Respiratory Medicine CME
Volume 2, Issue 2 , Pages 80-83, 2009

Peritoneal mesothelioma – a case report

Western Health and Social Care Trust, General Medicine, Erne Hospital, Cornagrade Road, Enniskillen, Northern Ireland BT74 6AY, UK

Received 21 August 2008; accepted 15 October 2008.

Article Outline

Summary 

Background

Peritoneal mesothelioma is a very rare diagnosis with an incidence of 1 case per 4–5 million of the population. It accounts for 20–30% of all mesothelioma type cancers. There is great interest in this disease entity amongst the medical community and indeed the general population due to the well-substantiated link between asbestos related exposure and mesothelioma.

Case presentation

In this article we report a case of a 77 year old man who presented with a one week history of breathlessness and a right pleural effusion. An incidental right upper quadrant abdominal mass was noted leading to ultrasound and subsequent CT scans. A large subhepatic mass was identified, in addition to pleural calcification and thickening. Biopsy and histological examination of the abdominal mass suggested a spindle cell tumour, most likely a mesothelioma. Thoracocentesis and cytology of the pleural fluid confirmed the diagnosis of a malignant mesothelioma. Our patient is a retired dairy farmer. A detailed occupational history revealed likely asbestos exposure when he worked as a plumber, approximately 50 years ago.

Discussion

Patients with peritoneal mesothelioma often present late, and as a result treatment is often palliative. Interventions include cytoreductive (debulking) surgery and intraperitoneal chemotherapy or radiotherapy. Peritoneal mesothelioma is a very rare disease entity, yet a diagnosis to be considered in a patient with an abdominal mass, previous asbestos exposure, and pleural calcification.

Keywords: Mesothelioma, Peritoneal, Asbestos

 

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Background 

Mesothelioma is a malignancy of the mesothelium, the serosal membrane that covers and protects the internal organs of the body. Malignant mesotheliomas predominantly affect the pleural mesothelium (50–60%) but can affect any anatomical mesothelial surface including the peritoneum (20–30%), the pericardium or indeed the tunica vaginalis testis of the male, or tunica serosa uteri in the female patient. The incidence of peritoneal mesothelioma worldwide is approximately one case per 4–5 million of the population, with an incidence of all mesotheliomas being in the range of one per 1 million. However, the incidence rates in industrialized countries are greater and ranges between 0.5 and three cases per million in men and between 0.2 and two cases per million in women.1 With malignant peritoneal mesothelioma being a relatively rare diagnosis there is limited data on the natural history of this condition.

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Case report 

A 77 year old man with a background history of Alzheimer's disease, ischaemic heart disease, carotid artery stenosis and gastric ulcers, presented with a one week history of breathlessness. There was no associated cough, haemoptysis, weight loss, anorexia or symptoms suggestive of heart failure. Initial assessment revealed reduced air entry and crepitations at the right base. He was apyrexial and inflammatory markers were slightly elevated (WCC 11.4 and CRP 36). A chest X-ray suggested right basal consolidation with an associated small effusion. He was initially treated for a community acquired pneumonia.

Further to vague abdominal discomfort and a palpable fullness in the right upper quadrant, an USS was performed. This showed a large (13cm) subhepatic heterogenous soft tissue mass. A CT of chest, abdomen and pelvis (Fig. 1) confirmed the presence of this mass. In addition, the mass was felt to be infiltrating the anterior abdominal wall and was closely related to the hepatic flexure. There were upper lobe emphysematous changes in the chest with bilateral pleural thickening and calcifications, in addition to an increasing right pleural effusion. A previous abdominal ultrasound 4 years ago was normal. Despite the close relation of the mass to the ascending colon, our patient did not have any signs of bowel obstruction.

An ultrasound-guided biopsy of the abdominal mass was performed, and histology identified a spindle cell tumour (Fig. 2). Possibilities at this stage were malignant mesothelioma, fibromatosis or gastrointestinal stromal tumour. Subsequent thoracocentesis and examination of pleural fluid confirmed the diagnosis of a malignant mesothelioma.

Our patient was a retired dairy farmer. Revisiting his occupational history revealed that he had worked as an assistant plumber for at least 2 years, approximately 50 years ago. He acknowledged working closing with pipes, and possible exposure to asbestos. After review by a respiratory specialist, he received talc pleurodesis. Due to the advanced nature of his condition he is not for any aggressive treatment. Management is very much palliative.

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Discussion 

Malignant peritoneal mesothelioma is a neoplasm originating from the mesothelial surface lining cells of the peritoneal serous cavities. Approximately 20–30% of all mesotheliomas affect the peritoneum. The association between asbestos exposure and peritoneal mesothelioma is less strong than in the case of pleural mesothelioma.1 In approximately 50% of peritoneal mesothelioma cases there is a history of asbestos exposure. It appears that the risk of mesothelioma and the risk of subsequent mortality correlates with cumulative exposure to asbestos fibres and also the type of fibre. Patients who have been exposed only or predominantly to chrysotile asbestos fibres contribute to a lower proportion of total deaths from peritoneal mesothelioma than those individuals exposed to amphibole fibres or mixed type of asbestos fibres.1 The latent period for asbestos-related peritoneal mesothelioma is shorter than that for the more common pleural mesothelioma, 20–30 years vs 30–40 years.2

Whilst asbestos is identified as the main known cause of the disease, other risk factors are likely to be involved in its aetiology and pathogenesis. Case reports have also noted peritoneal mesothelioma in patients following exposure to erionite and the radiological dye Thorotrast.3, 4 The role of other suspected risk factors, such as simian virus 40 infection and genetic predisposition, is unclear at present.

Peritoneal mesothelioma has a male predominance, and a median age of 65–69 years old.2 Although Deraco et al. report a patient diagnosed with a peritoneal mesothelioma aged just 22 years old.5 There is also evidence of a geographical variance in the incidence of peritoneal mesotheliomas amongst different populations, the highest incidence found in the Netherlands and Scotland.1

The diagnosis of peritoneal mesothelioma is often delayed, due to the relatively insidious mild non-specific symptomatology of the disease.6 The common presenting symptoms are vague and non-specific and include weight loss, usually with a full abdomen, malaise, and abdominal discomfort.

As with all mesotheliomas, the diagnosis of peritoneal mesothelioma can be challenging. Two peritoneal mesothelioma subtypes have been described based on findings on CT scanning. The ‘dry’ type of mesothelioma is associated with multiple small masses or a single dominant localized mass on CT with little or no ascites. In the “wet” type of mesothelioma, CT reveals widespread small nodules with ascites present, but no dominant mass.2

If ascites is present, paracentesis may be performed to obtain a sample of peritoneal fluid for cytological examination. However, fluid analysis offers limited diagnostic value. Instead a tissue biopsy of the intra-abdominal mass is required and subsequent immunocytochemical staining will yield a definitive diagnosis.

There are limited therapeutic options available for the physician when treating a patient with a malignant mesothelioma arising from the peritoneal cavity.7 As the diagnosis often made late in the disease process, the majority of patients are managed with palliative care. Palliative treatment is designed to reduce the rate at which the cancer spreads, and to provide symptomatic relief.

Options for those patients who are deemed suitable for more aggressive management are also limited. Surgery alone and/or intraperitoneal chemotherapy alone have proven to be similarly ineffective. In recent years, multimodality treatment of peritoneal mesothelioma has largely become the treatment of choice. The management of these patients includes cytoreductive (debulking) surgery involving the removal of all or nearly all visible tumour, combined with either intraperitoneal chemotherapy or radiotherapy.7 This multimodality treatment approach with cytoreductive surgery and intraperitoneal chemotherapy has resulted in a median survival of 50–60 months.8, 9

Overall survival remains poor; in the USA Surveillance, Epidemiology and End Results (SEER) cancer registry data median survival is 10 months and relative 5-year survival is 16%.10 In selected clinical series a longer survival has been reported with median survival greater than 50 months.11 Female patients have a significantly better prognosis than male patients.12

Feldman et al. report that favourable outcome is associated with age, tumour patho-biology, lack of invasive tumour growth, and minimal residual disease after tumour resection.7 In addition to the completeness of cytoreduction, the performance status and mitotic count are the strongest factors influencing overall survival and the best determinants of outcome.5

Altima (pemetrexed) approved by the U.S. Food and Drug Administration authority in 2003, is the first medicine developed to specifically treat mesothelioma. Altima used in combination with cisplatin, a commonly used chemotherapy agent, has been shown in clinical trials to be associated with an increased survival for mesothelioma patients.13 It is an anti-folate antineoplastic agent that acts by disrupting folate dependent metabolic processes.

Although no biological markers (epidermal growth factor receptor, p16, matrix metalloproteinase 2 and matrix metalloproteinase 9) have been shown to be of prognostic value,5 recent research in 2007 has identified a tumour marker that may be useful in monitoring tumour response to therapy and for screening at risk individuals. Robinson et al. identified a soluble mesothelin-related protein (SMRP) present in the serum that early clinical trials have identified as a marker of malignant mesothelioma with a sensitivity rate of 83% and specificity rate of 95%. Changes in serum SMRP levels are thought to parallel the clinical course and mesothelioma tumour size.14

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Conclusion 

Peritoneal mesothelioma is a very rare disease entity. This case report discusses the diagnostic challenges, treatment and recent advances in the area of malignant peritoneal mesothelioma. In a patient presenting with an unusual abdominal mass and co-existing pleural calcification, it may be important to explore a history of previous asbestos exposure. Recent research into peritoneal mesothelioma has identified a tumour marker that may be useful, not only in monitoring tumour response to therapy, but also for screening at risk individuals, i.e. those patients who have previous occupational asbestos exposure.

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Acknowledgements 

Dr Hasan Vazir (Consultant Pathologist, Altnagelvin Hospital, Londonderry, N Ireland).

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Funding 

None.

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Consent 

Written informed consent was obtained from the patient and from his next of kin for publication of this case report.

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Conflict of interest statement 

None to declare.

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References 

  1. Boffetta P. Epidemiology of peritoneal mesothelioma: a review. Annals of Oncology. 2007;18(6):985–990
  2. Available from: <www.mesotheliomaweb.org/peritoneal.htm>.
  3. Baris YI, Simonato L, Artvinli M, et al. Epidemiological and environmental evidence of the health effects of exposure to erionite fibres: a four-year study in the Cappadocian region of Turkey. International Journal of Cancer. 1987;39:10–17
  4. Andersson M, Wallin H, Jonsson M, et al. Lung carcinoma and malignant mesothelioma in patients exposed to thorotrast: incidence, histology and p53 status. International Journal of Cancer. 1995;63:330–336
  5. Deraco M, Nonaka D, Baratti D, et al. Prognostic analysis of clinicopathologic factors in 49 patients with diffuse malignant peritoneal mesothelioma treated with cytoreductive surgery and intraperitoneal hyperthermic perfusion. Annals of Surgical Oncology. 2006;13:229–237
  6. Scripcariu V. Malignant peritoneal mesothelioma. Chirurgia (Bucur). 2006;101:641–646
  7. Feldman A, Libutti S, Pingpank J, et al. Analysis of factors associated with outcome in patients with malignant peritoneal mesothelioma undergoing surgical debulking and intraperitoneal chemotherapy. Journal of Clinical Oncology. 2003;21(24):4560–4567
  8. Sterman DH. Advances in management of mesothelioma. Respirology. 2005;10:266–283
  9. Ahmed I, Koulaouzidis A, Iqbal J, et al. Malignant peritoneal mesothelioma as a rare cause of ascites: a case report. Journal of Medical Case Reports. 2008;2:121
  10. SEER Database . Surveillance, epidemiology, and end results (SEER) program. National Cancer Institute, DCCPS, surveillance research program, Cancer Statistics Branch. Available from: <http://www.seer.cancer.gov>
  11. Mohamed F, Sugarbaker PH. Peritoneal mesothelioma. Current Treatment Options in Oncology. 2002;3:375–386
  12. Sugarbaker PH, Welch L, Mohammed F, et al. A review of peritoneal mesothelioma at the Washington cancer institute. Surgical Oncology Clinics of North America. 2003;12(3):605–621
  13. Available from: <http://www.mesotheliomaweb.org/alimta.htm>.
  14. Robinson BW, Creaney J, Lake R, et al. Soluble mesothelin-related protein–a blood test for mesothelioma. Lung Cancer. 2005;49(Suppl. 1):S109–S111

PII: S1755-0017(08)00096-1

doi:10.1016/j.rmedc.2008.10.012

Respiratory Medicine CME
Volume 2, Issue 2 , Pages 80-83, 2009

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