heteroplasm

from The Century Dictionary.

• noun Any heterologous tissue. See heteroplasia.

from the GNU version of the Collaborative International Dictionary of English.

• noun An abnormal formation foreign to the economy, and composed of elements different from those are found in it in its normal condition.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun pathology Tissue growing in a part of the body where it does not normally occur.