Complex sentence: Usual Interstitial Pneumonia, commonly abbreviated UIP, is the name of a histopathological pattern seen in diffuse lung diseases, also referred to as "interstitial lung diseases".
Split into simpler sentences: Usual Interstitial Pneumonia, commonly abbreviated UIP, is the name of a histopathological pattern seen in diffuse lung diseases. Diffuse lung diseases are also referred to as "interstitial lung diseases".