Some work into the treatment of various cancers has looked at the possibility of suppressing or counteracting the effect of TAF in the hope that restricting the flow of blood to a tumour will restrict growth and spread. They commonly invade pleura and mediastinal lymph nodes and often metastasise to the brain and bones. They bear similarity to secondary tumours and must be distinguished by CT scans and other investigations to check for presence of a primary . Adenocarcinoma commonly arises around scar tissue and is also associated with asbestos exposure. One form of adenocarcinoma is often distinguished from others, bronchiolo-alveolar carcinoma, these characteristically have well differentiated bland cells which grow along alveolar ducts.
Adenocarcinomas are proportionally less common in non-smokers.
Close study by electron microscopy indicates that these types can probably be included with squamous or adenocarcinomas. The tumour grows over serosal surfaces, and interlobar fissures. The cells are epithelial and spindle types and occur in differing ratios, mitosis is infrequently seen. A common complication of mesothelioma is pleural effusion, particularly recurrent effusion, and it may present as such. Distinction between benign and malignant effusions is difficult.