polyp vs protrusion

polyp

noun
  • An abnormal growth protruding from a mucous membrane. 

  • A cylindrical coelenterate, such as the hydra, having a mouth surrounded with tentacles. 

protrusion

noun
  • The act of protruding. 

  • The state of being protruded. 

  • Anything that protrudes. 

How often have the words polyp and protrusion occurred in a corpus of books? (source: Google Ngram Viewer )