myeloma vs malignant tumor

myeloma and malignant tumor both are nouns.

Word	Noun	Adjective	Verb	Adverb
myeloma	Yes	No	No	No
malignant tumor	Yes	No	No	No

As nouns, malignant tumor is a hypernym of myeloma; that is, malignant tumor is a word with a broader meaning than myeloma:

myeloma: a tumor of the bone marrow (usually malignant) composed of cells normally found in bone marrow
malignant tumor: a tumor that is malignant and tends to spread to other parts of the body

Other hypernyms of myeloma include malignant neoplasm, metastatic tumor.

myeloma (noun)	malignant tumor (noun)
a tumor of the bone marrow (usually malignant) composed of cells normally found in bone marrow	a tumor that is malignant and tends to spread to other parts of the body