• (n.) An abnormal formation foreign to the economy, and composed of elements different from those are found in it in its normal condition.
Het'er·o·plasm noun [ Hetero- + Greek ... anything formed or molded.] An abnormal formation foreign to the economy, and composed of elements different from those are found in it in its normal condition. Dunglison. 
heteroplasm A tissue formed in a part where it does not normally occur.