Malignant vascular tumours of the pleura in “asbestos” workers and endothelial differentiation in malignant mesothelioma
- R L Attanoosa,
- S K Suvarnab,
- E Rheadc,
- M Stephensc,
- T J Lockee,
- M N Sheppardd,
- F D Pooleyf,
- A R Gibbsa
- aDepartment of Histopathology, Llandough Hospital, Cardiff, UK, bDepartment of Histopathology, Northern General Hospital, Sheffield, UK, cDepartment of Histopathology, North Staffordshire General Hospital, Stoke on Trent, UK, dDepartment of Histopathology, Royal Brompton Hospital, London, UK, eDepartment of Surgery, Northern General Hospital, Sheffield, UK, fDivision of Materials and Minerals, University of Wales, Cardiff, UK
- Dr R L Attanoos, Department of Histopathology, Llandough Hospital, Cardiff CF64 2XX, UK
- Received 11 November 1999
- Revision requested 20 March 2000
- Revised 11 July 2000
- Accepted 12 July 2000
Abstract
BACKGROUND Three cases of diffuse malignant vascular tumours of the pleura are described which mimicked malignant mesothelioma clinically and pathologically (so called “pseudomesothelioma”). All had occupational histories of exposure to asbestos. The relationship of these tumours to mesothelioma and asbestos exposure is discussed.
METHODS To examine the histogenetic relationship between mesothelioma and these three tumours an immunohistochemical analysis of vascular marker (CD31, CD34, and Von Willebrand factor) expression was undertaken in 92 cases of pleural mesothelioma, in addition to these three tumours. Electron microscopic fibre analysis of lung tissue was performed on each of the three cases to assess asbestos fibre content.
RESULTS Diffuse pleural epithelioid haemangioendotheliomas may closely resemble malignant mesothelioma clinically and pathologically but, of the 92 pleural mesotheliomas tested, none showed expression of CD31, CD34, and Von Willebrand factor. Although all three cases had claimed exposure to asbestos, ferruginous bodies typical of asbestos were only seen by light microscopy in case 2, and only in this subject was the asbestos fibre content raised in comparison with the range seen in a non-exposed background population. The latent period in the pleural epithelioid haemangioendotheliomas ranged from 18 to 60 years.
CONCLUSIONS Endothelial differentiation does not appear to occur in mesothelioma and therefore should be clearly separated from it. No definite association between pleural epithelioid haemangioendothelioma and exposure to asbestos can be made from this small series but further investigation is warranted.
