Pleomorphic is a word pathologists use to describe a group of cells that are very different from each other in either size or shape. Pleomorphic cells are abnormal and are more likely to be found in a cancerous tumour.
Because pleomorphic cells look very abnormal. your pathologist may order additional tests such as immunohistochemistry to try to learn more about the cells.
Pathologists also use the word pleomorphism to describe a tissue sample that shows pleomorphic cells.