mesothelioma in situ

It is virtually certain that the pathogenesis of mesothelial neoplasia includes a phase of "mesothelioma in situ". However, it is currently impossible to establish the diagnosis of mesothelioma in situ reliably in the absence of associated invasive mesothelial malignancy.

When the diagnosis of mesothelioma in situ has been reported, it has been based on the presence of a superficial proliferation of highly atypical mesothelial cells distributed as a single or small number of layered cells along a minimally inflamed papillated and edematous stromal surface.

The interpretation of this finding is complicated by the fact that invasive malignant mesothelioma can grow in lepidic fashion as single cells at its edges with extension along the pleural surface.

Until reliable molecular or immunohistochemical parameters are established, the diagnosis of mesothelioma in situ is best avoided.

An additional diagnosis of mesothelioma in situ in the presence of unequivocally invasive malignant mesothelioma adds little to either our current understanding of this disorder or to clinical management.

See also

 mesothelioma

• malignant mesothelioma