polyp vs tumor

polyp

noun
  • An abnormal growth protruding from a mucous membrane. 

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

tumor

noun
  • An abnormal growth; differential diagnosis includes abscess, metaplasia, and neoplasia. 

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