Cancer cells are anaplastic in that they "form backward" to an earlier de-differentiated state. the cells have nuclei that vary in size and shape, termed ___.

The cells have nuclei that vary in size and shape, termed pleomorphism.

Pleomorphism is usually defined in biology as the occurrence of multiple structural forms during the life cycle of an organism. In anaplasia, it represents multiple structural forms of nuclei. Pleomorphism is a characteristic feature found in malignant neoplasms, and dysplasia, but it can also be found in certain benign cell types.