 The tracheal cartilage externally had marked thickening and significant stiffness calcification, and the tracheal wall from the outside of the trachea to the mucosa measured 3 to 4 mm in thickness. 
The tracheal cartilage externally had marked thickening and significant stiffness calcification , and the tracheal wall from the outside of the trachea to the mucosa measured 3 to 4 mm in thickness .