A malignant neoplasm that arises from a pre-existing lower grade lesion, or as a result of a primary lesion that has spread to secondary sites, or due to a complication of a cancer treatment.
Comment:
Note that we currently treat secondary neoplasms as being neoplastic diseases that are derived from neoplasm; classes such as 'neoplasm', 'carcinoma' are implicitly primary. This may change in future.