Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.


Queen's English for tumor, see there.


1. Any swelling or tumefaction.
2. Synonym(s): neoplasm, tumour.
3. One of the four signs of inflammation (tumor, calor, dolor, rubor) enunciated by Celsus.
Synonym(s): tumour.
[L. tumor, a swelling]


A swelling. The term usually refers to any mass of cells resulting from abnormal degree of multiplication. Tumours may be BENIGN or MALIGNANT. Benign tumours enlarge locally, and are often enclosed in capsules, but do not invade tissue or spread remotely. Malignant tumours infiltrate locally and also seed off into lymphatic vessels and the bloodstream to establish secondary growths (metastases) elsewhere in the body.


a swelling, usually a morbid growth.


  • benign tumour non-invasive, encapsulated tumour; does not form metastases nor destroy local tissues; its bulk may distort surrounding tissues

  • bone tumour see Table 1

  • Ewing's tumour see Ewing's sarcoma

  • malignant tumour invasive tumour, usually non-encapsulated; forms metastases, destroys local tissues, tends to recur after excision and has a high mortality rate, unless treated aggressively

Table 1: Tumours arising in bone
Bone tumour typeExamples occurring in lower limb/foot
BenignAneurysmal bone cyst
Solitary osteochondroma
Simple/solitary bone cyst
Osteoid osteoma
Giant-cell tumour
Ewing's sarcoma
Osteogenic sarcoma


(tū'mŏr) Avoid the jargonistic use of this word as a synonym of neoplasm.
1. Any swelling or tumefaction.
2. One of the four signs of inflammation (the others are, calor, dolor, rubor) enunciated by Celsus.
Synonym(s): tumour.
[L. tumor, a swelling]

Patient discussion about tumour

Q. What is a brain tumor?

A. A brain tumour is any intracranial tumor normally either in the brain itself in the cranial nerves, in the brain envelopes, skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). It is created by abnormal and uncontrolled cell division. Primary (true) brain tumors (which start in the brain) are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain.

Q. Is this a tumor? I felt a lump in my breast a few days ago in the shower. Is this a Tumor? Help! I'm scared.

A. If you felt a lump in your breast then you should go see your Doctor to check whether or not it is something that could be dangerous.

Q. what is carcinoid tumors? I had my appendix removed and the doctor came in the room very shocked and said it was full of carcinoid tumors. Im scared to get them somewhere else.

A. ya I have pain all the time but the doctors wont give me anything cuz im so young they don't want me hooked on anything. thank you sooo much for being so kind.

More discussions about tumour
References in periodicals archive ?
Sertoli-Leydig cell tumour with heterologous element: a case report and a review of the literature.
The morphologic and immunohistochemical spectrum of 16 cases of sclerosing stromal tumour of the ovary.
This study was planned at a tertiary care hospital over a time period of nine years, from 2007 to 2016, all the cases of ovarian tumours diagnosed in the histopathology department were retrieved.
Slides of sex cord stromal tumours were reviewed and that case where Immunohistochemistry was done was also viewed.
Sex cord stromal tumours of the ovary are rare tumours, accounting for 5-7% of the total ovarian tumours.
Molecular pathogenesis of these groups of tumours is unknown; some have suggested mutation in FOXL 2 gene a transcription factor.
Sex cord-stromal tumours are rare tumours accounting for less than 7% of all ovarian tumours.
Sertoli leydig cell tumours were the next common group in our series.
Thecoma fibroma group is our third most common group; these are approximately one third as common as granulosa cell tumours.
Ovarian sex cord stromal tumours in children and young girls - a more than two decade clinicopathological experience in a developing country, Pakistan.
The activity of taxanes compared with bleomycin, etoposide, and cisplatin in the treatment of sex cord-stromal ovarian tumours.
Sertoli cell tumours of the ovary: a clinicopathologic and immunohistochemical study of 54 cases.