abnormal mass of tissue as a result of abnormal growth or division of cells
(Redirected from Tumour)

A neoplasm is tissue that is growing where it should not be. If they become a mass, they become a tumour. Tumours are either malignant (harmful) or benign (safe). Cancer, for example is malignant and sometimes spreads to other places on the body. Some tumours have a cause that makes them grow. For some tumours no cause is known.[1][2][3] A tumour usually forms as a lump or mass.[4]

A removed section of a colon with colon cancer. In the middle, the dark-red part is a tumor, as shown by the uncontrollable growth of cells.
Tasmanian devil with a tumour

Tumours can occur in humans and animals. In humans, tumors can occur because the genetic code of cells is modified too much, causing affected cells to divide and expand uncontrollably.[5] The Tasmanian Devils in Tasmania, Australia are in danger of becoming extinct because of a malignant tumour that grows on their face.[6]


  1. "Type-2 pericytes participate in normal and tumoral angiogenesis". American Journal of Physiology. Cell Physiology. 307 (1): C25-38. Jul 2014. doi:10.1152/ajpcell.00084.2014. PMC 4080181. PMID 24788248. {{cite journal}}: Cite uses deprecated parameter |authors= (help)
  2. Cooper GM (1992). Elements of human cancer. Boston: Jones and Bartlett Publishers. p. 16. ISBN 978-0-86720-191-8.
  3. Taylor, Elizabeth J. (2000). Dorland's Illustrated medical dictionary (29th ed.). Philadelphia: Saunders. p. 1184. ISBN 0721662544.
  4. Stedman's medical dictionary (28th ed.). Philadelphia: Lippincott Williams & Wilkins. 2006. p. Neoplasm. ISBN 0781733901.
  5. Tammela, Tuomas; Sage, Julien (2020). "Investigating Tumor Heterogeneity in Mouse Models". Annual Review of Cancer Biology. 4 (1): 99–119. doi:10.1146/annurev-cancerbio-030419-033413. PMC 8218894. PMID 34164589.
  6. Department of Primary Industry and Water.[permanent dead link] Tasmanian Devil Facial Tumour Disease