Mesothelioma of the pleura

This malignant tumor with a poor prognosis is related to asbestos exposure. It can arise in any mesothelium including pleura, pericardium, or peritoneum. The cells can be epithelioid (as seen here), sarcomatous or mixed. Sometimes a papillary pattern is seen.

In this section malignant cells are surrounded by dense collagen fibers. This could represent desmoplasia or invasion of a pre-existing pleural plaque, another entity related to asbestos.