noun.
A tumour that is caused by malignancies in precursor cells or blasts.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a tumor composed of immature undifferentiated cells
Word Usage
"Malignancies consist mainly of pulmonary blastoma and rhabdomyosarcoma in infants and young children, and bronchioloalveolar carcinoma in older children and adults."