Description
		
This is a section of right lung showing extensive interstitial fibrosis. Anthracosis is seen at the 
visceral pleural surface. 
		 History
		
This 65-year-old man had rheumatoid arthritis. He complained of progressive difficulty 
in breathing. Microscopy of the lung showed extensive advanced usual interstitial pneumonia 
(UIP). In one area there was a classic Caplan's nodule.