choristoblastoma

cho·ris·to·blas·to·ma

(kō-ris'tō-blas-tō'mă),
An autonomous neoplasm composed of relatively undifferentiated cells of a choristoma.
[choristoma + blastoma]

choristoblastoma

(1) Choristoma.
(2) An obsolete term for either:
• A neoplasm of primitive cells not native to the site at which they develop; or
• A malignant tumour arising in choristoma.