[an″ah-pla´zhah] loss of differentiation of cells and their orientation to each other, a characteristic of tumor cells; called also dedifferentiation and undifferentiation.
undifferentiation
(un-dif?er-en-she-a'shun) [AS. un, not, + L. differens, bearing apart] An alteration in cell character to a more embryonic type or toward a malignant state. Synonym: anaplasia