choristoma

{{Short description|Masses of normal tissues found in an abnormal location}}

Choristomas, a form of heterotopia, are masses of normal tissues found in abnormal locations.{{DorlandsDict|two/000020903|Choristoma}}{{cite book|last1=Lee|first1=Kenneth H.|last2=Roland|first2=Peter S.|title=Encyclopedia of Otolaryngology, Head and Neck Surgery |chapter=Heterotopias, Teratoma, and Choristoma |year=2013|pages=1179–1183|doi=10.1007/978-3-642-23499-6_642|isbn=978-3-642-23498-9}}{{cite journal|last1=Jorquera|first1=JessicaPatricia Correa|last2=Rubio-Palau|first2=Josep|last3=Cazalla|first3=AsteriaAlbert|last4=Rodríguez-Carunchio|first4=Leonardo|title=Choristoma: A rare congenital tumor of the tongue|journal=Annals of Maxillofacial Surgery|year=2016|volume=6|issue=2|pages=311–313|doi=10.4103/2231-0746.200342|pmc=5343649|pmid=28299279 |doi-access=free }}{{cite journal|last1=Goswamy|first1=Monika|last2=Tabasum|first2=Syeda|last3=Kudva|first3=Praveen|last4=Gupta|first4=Shikha|title=Osseous choristoma of the periodontium|journal=Journal of Indian Society of Periodontology|date=2012|volume=16|issue=1|pages=120–2|doi=10.4103/0972-124X.94619|pmc=3357020|pmid=22628977 |doi-access=free }} In contrast to a neoplasm or tumor, the growth of a choristoma is normally regulated.{{Cite journal|last1=Birbrair|first1=Alexander|last2=Zhang|first2=Tan|last3=Wang|first3=Zhong-Min|last4=Messi|first4=Maria Laura|last5=Olson|first5=John D.|last6=Mintz|first6=Akiva|last7=Delbono|first7=Osvaldo|date=2014-07-01|title=Type-2 pericytes participate in normal and tumoral angiogenesis|journal=American Journal of Physiology. Cell Physiology|language=en|volume=307|issue=1|pages=C25–C38|doi=10.1152/ajpcell.00084.2014|issn=0363-6143|pmc=4080181|pmid=24788248}}

It is different from a hamartoma. The two can be differentiated as follows: a hamartoma is disorganized overgrowth of tissues in their normal location (e.g., Peutz–Jeghers polyps), while a choristoma is normal tissue growth in an abnormal location (e.g., osseous choristoma,{{Cite journal|last=Adhikari|first=Bhoj Raj|title=Osseous choristoma of the tongue: two case reports|journal=Journal of Medical Case Reports|volume=2016|pages=59|pmc=4794853|year=2016|pmid=26983573|doi=10.1186/s13256-016-0840-8 |doi-access=free }} gastric tissue located in distal ileum in Meckel diverticulum).