Document M4JLKZgMRB8rRx3BDKEE1XaXV

-3 - (Next Slide) I mentioned pleural thickening because this is a rather characteristic finding in asbestosis. It occurs early in the disease and it may be the "only change, at least, for some time. It is not a feature of other kinds of pneumoconiosis or dust diseases of the lungs. The thickened pleura may become calcified to give what is called a pleural plaque. These plaques would occur on the surface of the lung or on the chest wall and even on the diaphragm. The calcification rarely occurs in less than 20 years after the first exposure and it is generally a feature of anthpphyllite exposure although it can be seen with exposure to other types of asbestos. The exposures are not always occupational. Pleural plaques have been observed in persons who lived adjacent or near to a source of asbestos. Persons in the neighborhood of an asbestos mine for exasple, have been found to have these pleural plaques. (Next Slide) I have some information on asbestos bodies or ferruginous bodies as some people prefer to call them. This is included because if one talks about asbestos or asbestosis very long, he is probably going to hear the term asbestos bodies. These are fibers coated with an ironcontaining protein which gives a characteristic golden-brown beading along the length of tbs fiber. Often the fibers become thickened at each end to font a characteristic dumbbell appearance which can be seen under the microscope. Asbestos bodies in the lung or sputum are not pathognomic of asbestosis, that is, they are not diagnostic. Their presence does not mean the existence of asbestosis; however, this was thought to be the case and originally, asbestos bodies were called asbestosis bodies. However, the feeling is now that they indicate merely a past exposure to asbestos. DUP 0901981