Mixed tumor
{{Short description|Tumor derived from multiple tissue types}}
A mixed tumor is a tumor that derives from multiple tissue types.{{cite web|url=https://medical-dictionary.thefreedictionary.com/mixed+tumor|website=TheFreeDictionary (by Farlex)|title=mixed tumor|access-date=2020-04-26}} In turn citing:
-For requiring neoplastic types: Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition
- Without further specification:
- Farlex Partner Medical Dictionary A biplastic tumor or biphasic tumor has two tissue types.For "biplastic tumor": {{cite journal| author=Salati SA| title=Breast fibroadenomas: a review in the light of current literature. | journal=Pol Przegl Chir | year= 2020 | volume= 93 | issue= 1 | pages= 40–48 | pmid=33729177 | doi=10.5604/01.3001.0014.5676 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=33729177 }}For "biphasic tumor": {{cite journal|last1=Santosh|first1=Arvind Babu Rajendra|title=Histogenetic Concepts, Terminology and Categorization of Biphasic Tumours of the Oral and Maxillofacial Region|journal=Journal of Clinical and Diagnostic Research|volume=8|issue=2|pages=266–70|year=2014|issn=2249-782X|doi=10.7860/JCDR/2014/7506.4078|pmid=24701553|pmc=3972583}}
True versus false
- A true mixed tumor contains multiple types of neoplastic cells.{{cite journal|last1=Fowler|first1=Melissa H|last2=Fowler|first2=Jason|last3=Ducatman|first3=Barbara|last4=Barnes|first4=Leon|last5=Hunt|first5=Jennifer L|title=Malignant mixed tumors of the salivary gland: a study of loss of heterozygosity in tumor suppressor genes|journal=Modern Pathology|volume=19|issue=3|year=2006|pages=350–355|issn=0893-3952|doi=10.1038/modpathol.3800533|doi-access=|pmid=16400327 }} Some sources require the included tissue types to be neoplastic for the definition of mixed tumor.
- A "false" mixed tumor contains one type of neoplastic cells, but which have more than one appearance. For example, benign pleomorphic salivary gland tumors may have some tumors cells that form pseudocartilage. Yet, all the tumor cells have similar myoepithelial profile on immunohistochemistry, and are thus classified as one cell type.
Reactive or adaptive changes to a tumor does not count towards a classification as mixed. Such changes include angiogenesis (blood vessel proliferation) and/or desmoplasia (proliferation of connective tissue).{{cite journal|last1=Miller|first1=Daniel D|last2=Emley|first2=Andrew|last3=Yang|first3=Shi|last4=Richards|first4=Joanna E|last5=Lee|first5=Jung Eun|last6=Deng|first6=April|last7=Hoang|first7=Mai P|last8=Mahalingam|first8=Meera|title=Mixed versus pure variants of desmoplastic melanoma: a genetic and immunohistochemical appraisal|journal=Modern Pathology|volume=25|issue=4|year=2011|pages=505–515|issn=0893-3952|doi=10.1038/modpathol.2011.196|doi-access=free|pmid=22157936 }}
Number of cell types
- A biplastic tumor or biphasic tumor consists of two tissue types.
- A teratoma is the main tumor type that often includes more than two tissue types. They may form for example hair, muscle, teeth, and/or bone.{{cite web|title=NCI Dictionary of Cancer Terms|url=https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=44248|website=National Cancer Institute|access-date=20 December 2017|date = 2011-02-02}}
Examples of true mixed tumors
File:Histopathology of carcinosarcoma, annotated.png of a carcinosarcoma of the ovary. H&E stain, showing both carcinomatous and sarcomatous elements]]
