Did he see any cells under a microscope? Did they try to squeeze anything out of it? Is it hard or soft, or does it seem like fluid? If it is a feather cyst, they can form an abscess, and their could be solid yellow pus inside it. Exploring it with a sterile needle and sterilizing the skin with disinfectant, can lead to finding an ingrown feather inside.
	
		
			
		
		
	
				
			 
	 
 
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		