noun
malignant neoplasm; malignant tumor
Formal medical term; in everyday conversation, 悪性腫瘍 (あくせいしゅよう) or simply がん is more common.
病理検査の結果、悪性新生物と診断された。
The pathology report diagnosed it as a malignant neoplasm.
悪性新生
Early detection of malignant neoplasms is important.