Tumor

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Categories: Anatomical pathology | Oncology

For malignant tumors specifically, see cancer.

A Tumor or tumour (via Old French tumour from Latin tumor "swelling")^[1] originally meant an abnormal swelling of the flesh. In contemporary English, tumor has evolved to become synonymous with neoplasia ^[2], all other forms being called swelling ^[3]. This tendency has also become common in medical literature. The noun tumefaction, derived from the adjective tumefied, is the current medical term for non-neoplastic tumors ^[4].

Causes

Tumors and/or swellings can be caused by:

Neoplasia, an abnormal proliferation of tissues. Most (not all) neoplasms cause a tumor. Neoplasms (or tumors) may be benign or malignant (cancer).

Non-neoplastic causes :

Inflammation, by far the most common cause; tumor is one of the classic signs of inflammation.^[5] The lump following a blow on the head is a typical example. Infection is another common cause of inflammation.

- Edema, the accumulation of an excessive amount of fluid in the tissues, either with or without inflammation.
- Malformation, a congenital anomaly in the architecture of a tissue. A typical example is an epidermal nevus.
- Cyst, the accumulation of fluid in a closed structure. Breast cysts are a typical example.
- Hemorrhage in a closed structure.

Other forms of swelling are part of the normal functions of the body and may or may not be included as causes of tumor. Examples include enlargement of the uterus in pregnancy and erection of the penis.

This article is intentionally kept short. For a detailed discussion, see Cancer.

References

^ t_22/12830354 at Dorland's Medical Dictionary
^ Tumor in MedlinePlus Medical Encyclopedia]
^ swelling, in MedlinePlus Medical Encyclopedia
^ t_22/12830299 at Dorland's Medical Dictionary
^ eMedicine/Stedman Medical Dictionary Lookup!. Retrieved on 2008-01-08.

v • d • e Pathology: Cancer, Tumors, Neoplasms, and oncology (C00-D48, 140-239)
Benign tumors	Hyperplasia - Cyst - Pseudocyst - Hamartoma - Benign tumor
Malignant progression	Dysplasia - Carcinoma in situ - Cancer - Metastasis
Topography	lip, oral cavity and pharynx: Oral - Head/Neck - Nasopharyngeal digestive system: tract (Esophagus, Stomach, Small intestine, Colon/rectum, Appendix, Anus) - glands (Liver, Bile duct, Gallbladder, Pancreas) respiratory system: Larynx - Lung bone, articular cartilage, skin, and connective tissue: Bone - Skin - Blood urogenital: breast and female genital organs (Breast, Vagina, Cervix, Uterus, Endometrium, Ovaries) - male genital organs (Penis, Prostate, Testicles) - urinary organs (Kidney, Bladder) nervous system: Eye (Uvea) - Brain endocrine system: Thyroid (Papillary, Follicular, Medullary, Anaplastic) - Adrenal tumor (Adrenocortical carcinoma, Pheochromocytoma) - Pituitary
Misc.	Tumor suppressor genes/oncogenes - Staging/grading - Carcinogenesis - Carcinogen - Research - Paraneoplastic syndrome - List of oncology-related terms