testicular cancer vs seminoma

testicular cancer and seminoma both are nouns.

Word	Noun	Adjective	Verb	Adverb
testicular cancer	Yes	No	No	No
seminoma	Yes	No	No	No

As nouns, testicular cancer and seminoma are synonyms defined as:

testicular cancer and seminoma: malignant tumor of the testis; usually occurring in older men

testicular cancer (noun)	seminoma (noun)
malignant tumor of the testis; usually occurring in older men	malignant tumor of the testis; usually occurring in older men