tumor

tumor — noun

1. A lump of abnormal tissue that forms when cells in a part of the body divide muc

1.nounB2
Definition

A lump of abnormal tissue that forms when cells in a part of the body divide much faster than normal and survive longer than they should, sometimes pressing on nearby organs or causing other health problems.

Example

Doctors discovered a small tumor in Naoko's lung during a routine check-up.

discovered in [body part] during a routine check-up

The biopsy showed that the tumor in Élise's breast was benign and not life-threatening.

collocation: benign tumor / malignant tumor

Common collocations
  • benign tumor
  • malignant tumor
  • brain tumor
  • tumor cells
  • tumor growth
Synonyms
  • growth

    a less formal, everyday word for an abnormal lump of tissue

  • mass

    a clinical term used in medical imaging reports for any abnormal area of tissue

  • neoplasm

    the technical medical term for any abnormal new growth of tissue

Grammar Patterns

tumor + in/on + [body part]

tumor + of + [body part]

Usage Note

Frequently paired with 'benign' (not cancer, does not spread) or 'malignant' (cancerous, can invade other tissues). 'Tumor' is the American spelling; the British spelling is 'tumour'.

Common Mistakes

The doctor found a tumor, which means I have cancer.
The doctor found a tumor, but the biopsy showed it was benign.
Not all tumors are cancer; a 'benign' tumor does not spread to other parts of the body.

Word family

  • tumorous
    adjectiveC1
  • tumoral
    adjectiveC1

Synonym discussion

Sense: noun/1

All three words describe abnormal tissue in the body, but they differ in formality and precision. 'Growth' is the least technical and most common in everyday speech — a patient might say 'I have a growth on my neck' without knowing whether it is a tumor. 'Mass' is a neutral radiology term; a doctor might say 'a suspicious mass was seen on the scan' before any diagnosis is made, so it leaves the nature of the tissue more open than 'tumor' does. 'Neoplasm' is the most precise medical term, used in pathology reports and academic writing to mean any abnormal new tissue growth, whether benign or malignant. In most conversations with patients, doctors prefer 'tumor' or 'growth' because 'neoplasm' sounds unnecessarily technical. For example: 'The radiologist saw a small mass on the X-ray, and the biopsy confirmed it was a benign tumor.'

growth ↗mass ↗neoplasm

Common collocations

Nouns

Phrases

  • remove a tumor
  • shrink a tumor
  • treat a tumor
  • diagnose a tumor
  • tumor cells

Prepositions

Etymology

LatinEnglish

The word 'tumor' comes directly from Latin 'tumor', meaning 'a swelling', which itself comes from the Latin verb 'tumēre' (to swell). In ancient medicine, any visible swelling was called a tumor. Over time the meaning narrowed to describe abnormal tissue growth caused by uncontrolled cell division, though the original 'swelling' sense survives in older medical writing.