A mixed tumor is a tumor that derives from multiple tissue types.
[ 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": ][For "biphasic tumor": ]
True versus false
*A ''true'' mixed tumor contains multiple types of
neoplastic
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
cells.
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
Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of Antibody, antibodies binding specifically to antigens in biological tissues. Alber ...
, 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
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature mainly by processes of sprouting and ...
(blood vessel proliferation) and/or desmoplasia
In medicine, desmoplasia is the growth of fibrous connective tissue. It is also called a desmoplastic reaction to emphasize that it is secondary to an insult (medical), insult. Desmoplasia may occur around a neoplasm, causing dense fibrosis arou ...
(proliferation of connective tissue).
Number of cell types
*A ''biplastic tumor'' or ''biphasic tumor'' consists of two tissue types.teratoma
A teratoma is a neoplasia, tumor made up of several types of biological tissue, tissue, such as hair, muscle, Human tooth, teeth, or bone. Teratomata typically form in the tailbone (where it is known as a sacrococcygeal teratoma), ovary, or test ...
is the main tumor type that often includes more than two tissue types. They may form for example hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and ...
, muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
, teeth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
, and/or bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
.
Examples of true mixed tumors
References
{{Oncology-stub}
Neoplasms