[1] : The Collaborative International Dictionary of English v.0.48

malignant neoplasm \malignant neoplasm\ n. med.,
   same as malignancy4.

   syn: malignancy, malignance, malignant tumor, metastatic
        tumor.
        wordnet 1.5

[2] : WordNet (r) 2.0

malignant neoplasm
     n : a tumor that is malignant and tends to spread to other parts
         of the body syn: malignant tumor, metastatic tumor
see also:
malignant tumor metastatic tumor 

Malignant >> M Words
Malignant, definition of term: Malignant
malignant_pag1.html

Neoplasm >> N Words
Neoplasm, definition of term: Neoplasm
neoplasm_pag1.html

Malignant Melan >> M Words
Malignant Melan, definition of term: Malignant Melan
malignant+melan_pag1.html

Malignant Tumor >> M Words
Malignant Tumor, definition of term: Malignant Tumor
malignant+tumor_pag1.html