Abernethy published the first classification of tumors based on pathologic anatomy. "Abernethy is best known for his lectures and writings on surgery and for the first attempt at classification of tumors, some of which he considered hereditary." "His classification divided tumors into several types of sarcomas, such as: common vascular, adipose, pancreatic, cystic, mammary, tuberculated, medullary, and carcinomatous, each illustrated by one or more of his 'cases.'

"ABERNETHY'S CLASSIFICATION

1. Common Vascular or Organized Sarcoma
2. Adipose Sarcoma
3. Pancreatic Sarcoma
4. Cystic Sarcoma
5. Mastoid or Mammary Sarcoma
6. Tuberculated Sarcoma
7. Medullary Sarcoma
8. Carcinomatous Sarcoma

"With his accurate observations, Abernethy provided much information concerning tumors upon which later scientists could build. However, almost 150 years later, with highly sophisticated equipment, we are still trying to solve the enigma of cancer" (Krush, Anne J., "The Classification of Tumors by John Abernethy Early in the Nineteenth Century," Transactions Nebraska Academy of Sciences and Affiliated Societies. [1980] 290).

A pupil of John Hunter, Abernethy became a leading surgeon in London. He was most industrious, and it is said that not even on his wedding day did he fail to give his usual daily lecture at St. Bartholomew’s Hospital. His book was, in the view of D’Arcy Power, epoch-making; on pp. 234-92 he recorded the first successful ligation of the external iliac artery for aneurysm, an operation carried out by Abernethy in 1796.