A benign tumor is a mass of
cells (
tumor
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 ...
) that does not
invade neighboring tissue or
metastasize
Metastasis is a pathogenic agent's spreading from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, ...
(spread throughout the body). Compared to
malignant (cancerous) tumors, benign tumors generally have a slower
growth rate. Benign tumors have relatively well
differentiated cells. They are often surrounded by an outer surface (fibrous sheath of
connective tissue
Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...
) or stay contained within the
epithelium
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...
. Common examples of benign tumors include
moles and
uterine fibroids.
Some forms of benign tumors may be harmful to health. Benign tumor growth causes a
mass effect
''Mass Effect'' is a military science fiction media franchise created by Casey Hudson. The franchise depicts a distant future where humanity and several alien civilizations have colonized the galaxy using technology left behind by Elder race, a ...
that can compress neighboring tissues. This can lead to nerve damage, blood flow reduction (
ischemia
Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...
), tissue death (
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
), or organ damage. The health effects of benign tumor growth may be more prominent if the tumor is contained within an enclosed space such as the
cranium,
respiratory tract
The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respirato ...
,
sinus, or bones. For example, unlike most benign tumors elsewhere in the body, benign
brain tumor
A brain tumor (sometimes referred to as brain cancer) occurs when a group of cells within the Human brain, brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign ...
s can be life-threatening. Tumors may exhibit behaviors characteristic of their cell type of origin; as an example,
endocrine
The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant organs. In vertebrates, the hypotha ...
tumors such as
thyroid adenomas and
adrenocortical adenomas may overproduce certain
hormone
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...
s.
The word ''benign'' means . However, a benign tumor is not ''benign'' in the usual sense; the name merely specifies that it is not "malignant", i.e. cancerous. While benign tumors usually do not pose a serious health risk, they can be harmful or fatal. Many types of benign tumors have the potential to become cancerous (
malignant
Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer.
A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...
) through a process known as
tumor progression. For this reason and other possible harms, some benign tumors are removed by surgery. When removed, benign tumors usually do not return. Exceptions to this rule may indicate malignant transformation.
Signs and symptoms
Benign tumors are very diverse; they may be asymptomatic or may cause specific symptoms, depending on their anatomic location and tissue type. They grow outward, producing large, rounded masses which can cause what is known as a "mass effect". This growth can cause compression of local tissues or organs, leading to many effects, such as blockage of ducts, reduced blood flow (
ischaemia), tissue death (
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
) and nerve pain or damage.
Some tumors also produce hormones that can lead to life-threatening situations.
Insulinomas can produce large amounts of insulin, causing
hypoglycemia
Hypoglycemia (American English), also spelled hypoglycaemia or hypoglycæmia (British English), sometimes called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's tria ...
.
Pituitary adenomas can cause elevated levels of hormones such as
growth hormone and
insulin-like growth factor-1, which cause
acromegaly
Acromegaly is a disorder that results in excess growth of certain parts of the human body. It is caused by excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There ...
;
prolactin
Prolactin (PRL), also known as lactotropin and mammotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secr ...
;
ACTH and
cortisol
Cortisol is a steroid hormone in the glucocorticoid class of hormones and a stress hormone. When used as medication, it is known as hydrocortisone.
Cortisol is produced in many animals, mainly by the ''zona fasciculata'' of the adrenal corte ...
, which cause
Cushing's disease
Cushing's disease is one cause of Cushing's syndrome characterised by increased secretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary (secondary hypercortisolism). This is most often as a result of a pituitary adenoma (spec ...
;
TSH, which causes
hyperthyroidism
Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperth ...
; and
FSH and
LH.
Bowel
intussusception can occur with various benign colonic tumors.
Cosmetic effects can be caused by tumors, especially those of the skin, possibly causing psychological or social discomfort for the person with the tumor.
Vascular tissue tumors can bleed, in some cases leading to
anemia
Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availabl ...
.
Causes
PTEN hamartoma syndrome
PTEN hamartoma syndrome encompasses
hamartomatous disorders characterized by genetic mutations in the
PTEN tumor suppressor gene, including
Cowden syndrome,
Bannayan–Riley–Ruvalcaba syndrome,
Proteus syndrome
Proteus syndrome is a rare genetic disorder that can cause tissue overgrowth involving all three Germ layer, embryonic lineages. Patients with Proteus syndrome tend to have an increased risk of embryonic tumor development.Freedberg, et al. (2003). ...
and
Proteus-like syndrome. Absent or dysfunctional PTEN protein allows cells to over-proliferate, causing hamartomas.
Cowden syndrome is an
autosomal dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...
genetic disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders ...
characterized by multiple benign
hamartomas (
trichilemmomas and mucocutaneous papillomatous papules) as well as a predisposition for cancers of multiple organs including the breast and thyroid.
Bannayan–Riley–Ruvalcaba syndrome is a
congenital disorder
A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...
characterized by hamartomatous intestinal polyposis,
macrocephaly
Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a Heredity, familial genetic characteristic. People diagnosed with macrocephaly will receive further medical ...
,
lipomatosis,
hemangiomatosis and
glans penis
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...
macules.
Proteus syndrome
Proteus syndrome is a rare genetic disorder that can cause tissue overgrowth involving all three Germ layer, embryonic lineages. Patients with Proteus syndrome tend to have an increased risk of embryonic tumor development.Freedberg, et al. (2003). ...
is characterized by
nevi, asymmetric overgrowth of various body parts, adipose tissue dysregulation,
cystadenomas,
adenoma
An adenoma is a benign tumor of epithelium, epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organ (anatomy), organs, including the adrenal glands, pituitary gland, thyroid, prosta ...
s, vascular malformation.
Familial adenomatous polyposis
Familial adenomatous polyposis (FAP) is a familial
cancer syndrome caused by mutations in the
APC gene. In FAP,
adenoma
An adenoma is a benign tumor of epithelium, epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organ (anatomy), organs, including the adrenal glands, pituitary gland, thyroid, prosta ...
tous polyps are present in the
colon. The polyps progress into
colon cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel ...
unless removed.
The APC gene is a
tumor suppressor. Its protein product is involved in many cellular processes. Inactivation of the APC gene leads to the buildup of a protein called
β-catenin. This protein activates two
transcription factors:
T-cell factor (TCF) and
lymphoid enhancer factor (LEF). These factors cause the upregulation of many genes involved in cell
proliferation,
differentiation,
migration
Migration, migratory, or migrate may refer to: Human migration
* Human migration, physical movement by humans from one region to another
** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
and
apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...
(programmed cell death), causing the growth of benign tumors.
Tuberous sclerosis complex
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by mutations in the genes
TSC1 and
TSC2. TSC1 produces the protein
hamartin. TSC2 produces the protein
tuberin. This disorder presents with many benign hamartomatous tumors including
angiofibroma
Angiofibroma (AGF) is a descriptive term for a wide range of benign skin or mucous membrane (i.e. the outer membrane lining body cavities such as the mouth and nose) lesions in which individuals have:
# benign papules, i.e. pinhead-sized elevatio ...
s, renal
angiomyolipomas, and pulmonary
lymphangiomyomatosis. Tuberin and hamartin inhibit the
mTOR protein in normal cellular physiology. Inactivation of the TSC tumor suppressors causes an increase in mTOR activity. This leads to the activation of genes and the production of proteins that increase cell growth.
Von Hippel–Lindau disease
Von Hippel–Lindau disease is a dominantly inherited cancer syndrome that significantly increases the risk of various tumors. This includes benign
hemangioblastoma
Hemangioblastomas, or haemangioblastomas, are vascular tumors of the central nervous system that originate from the vascular system, usually during middle age. Sometimes, these tumors occur in other sites such as the spinal cord and retina. They m ...
s and malignant
pheochromocytomas,
renal cell carcinomas,
pancreatic endocrine tumors, and
endolymphatic sac tumors. It is caused by genetic mutations in the
Von Hippel–Lindau tumor suppressor gene. The VHL protein (pVHL) is involved in cellular signaling in oxygen starved (
hypoxic) cells. One role of pVHL is to cause the cellular degradation of another protein,
HIF1α. Dysfunctional pVHL leads to accumulation of HIF1α. This activates several genes responsible for the production of substances involved in cell growth and blood vessel production:
VEGF,
PDGFβ,
TGFα and
erythropoietin
Erythropoietin (; EPO), also known as erythropoetin, haematopoietin, or haemopoietin, is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia; it stimulates red blood cell production ( erythropoiesis) in th ...
.
Bone tumors
Benign tumors of bone can be similar macroscopically and require a combination of a clinical history with
cytogenetic, molecular, and radiologic tests for diagnosis.
Three common forms of benign bone tumors with are
giant cell tumor of bone,
osteochondroma, and
enchondroma
Enchondroma is a type of benign bone tumor belonging to the group of cartilage tumors. There may be no symptoms, or it may present typically in the short tubular bones of the hands with a swelling, pain or pathological fracture.
Diagnosis i ...
; other forms of benign bone tumors exist but may be less prevalent.
Giant cell tumors
Giant cell tumors of bone frequently occur in long bone epiphyses of the
appendicular skeleton or the
sacrum
The sacrum (: sacra or sacrums), in human anatomy, is a triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30.
The sacrum situates at the upper, back part of the pelvic cavity, ...
of the
axial skeleton
The axial skeleton is the core part of the endoskeleton made of the bones of the head and trunk of vertebrates. In the human skeleton, it consists of 80 bones and is composed of the skull (28 bones, including the cranium, mandible and the midd ...
. Local growth can cause destruction of neighboring cortical bone and soft tissue, leading to pain and limiting range of motion. The characteristic radiologic finding of giant cell tumors of bone is a lytic lesion that does not have marginal
sclerosis of bone. On histology, giant cells of fused osteoclasts are seen as a response to neoplastic mononucleated cells. Notably, giant cells are not unique among benign bone tumors to giant cell tumors of bone. Molecular characteristics of the neoplastic cells causing giant cell tumors of bone indicate an origin of pluripotent mesenchymal stem cells that adopt preosteoblastic markers. Cytogenetic causes of giant cell tumors of bone involve
telomere
A telomere (; ) is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes (see #Sequences, Sequences). Telomeres are a widespread genetic feature most commonly found in eukaryotes. In ...
s. Treatment involves surgical curettage with adjuvant
bisphosphonate
Bisphosphonates are a class of drugs that prevent the loss of bone density, used to treat osteoporosis and similar diseases. They are the most commonly prescribed to treat osteoporosis.
Evidence shows that they reduce the risk of fracture in ...
s.
Osteochondroma
Osteochondromas form cartilage-capped projections of bone. Structures such as the marrow cavity and cortical bone of the osteochondroma are contiguous to those of the originating bone. Sites of origin often involve
metaphyses of long bones. While many osteochondromas occur spontaneously, there are cases in which several osteochondromas can occur in the same individual; these may be linked to a genetic condition known as hereditary multiple osteochondromas. Osteochondroma appears on X-ray as a projecting mass that often points away from joints.
These tumors stop growing with the closure of the parental bone's growth plates. Failure to stop growth can be indicative of transformation to malignant chondrosarcoma. Treatment is not indicated unless symptomatic. In that case, surgical excision is often curative.
Enchondroma
Enchondromas are benign tumors of hyaline cartilage. Within a bone, enchondromas are often found in metaphyses. They can be found in many types of bone, including small bones, long bones, and the axial skeleton. X-ray of enchondromas shows well-defined borders and a stippled appearance.
Presentation of multiple enchondromas is consistent with multiple
enchondromatosis (
Ollier Disease). Treatment of enchondromas involves surgical curettage and grafting.
Benign soft tissue tumors
Lipomas
Lipomas are benign, subcutaneous tumors of fat cells (
adipocyte
Adipocytes, also known as lipocytes and fat cells, are the cell (biology), cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes through ...
s). They are usually painless, slow-growing, and mobile masses that can occur anywhere in the body where there are fat cells, but are typically found on the trunk and upper extremities.
Although lipomas can develop at any age, they more commonly appear between the ages of 40 and 60.
Lipomas affect about 1% of the population, with no documented sex bias, and about 1 in every 1000 people will have a lipoma within their lifetime.
The cause of lipomas is not well defined. Genetic or inherited causes of lipomas play a role in around 2-3% of patients.
In individuals with inherited familial syndromes such as
Proteus syndrome
Proteus syndrome is a rare genetic disorder that can cause tissue overgrowth involving all three Germ layer, embryonic lineages. Patients with Proteus syndrome tend to have an increased risk of embryonic tumor development.Freedberg, et al. (2003). ...
or
Familial multiple lipomatosis, it is common to see multiple lipomas across the body.
These syndromes are also associated with specific symptoms and sub-populations. Mutations in
chromosome 12 have been identified in around 65% of lipoma cases.
Lipomas have also been shown to be increased in those with
obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...
,
hyperlipidemia
Hyperlipidemia is abnormally high levels of any or all lipids (e.g. fats, triglycerides, cholesterol, phospholipids) or lipoproteins in the blood. citing: and The term ''hyperlipidemia'' refers to the laboratory finding itself and is also use ...
, and
diabetes mellitus
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained hyperglycemia, high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or th ...
.
Lipomas are usually diagnosed clinically, although imaging (
ultrasound
Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...
,
computed tomography
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...
, or
magnetic resonance imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...
) may be utilized to assist with the diagnosis of lipomas in atypical locations.
The main treatment for lipomas is surgical excision, after which the tumor is examined with
histopathology
Histopathology (compound of three Greek words: 'tissue', 'suffering', and '' -logia'' 'study of') is the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopatholog ...
to confirm the diagnosis.
The prognosis for benign lipomas is excellent and recurrence after excision is rare, but may occur if the removal was incomplete.
Mechanism
Benign vs malignant

One of the most important factors in classifying a tumor as benign or malignant is its invasive potential. If a tumor lacks the ability to invade adjacent
tissues or spread to distant sites by metastasizing then it is benign, whereas invasive or metastatic tumors are malignant.
For this reason, benign tumors are not classed as cancer.
Benign tumors will grow in a contained area usually encapsulated in a fibrous
connective tissue
Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...
capsule. The growth rates of benign and malignant tumors also differ; benign tumors generally grow more slowly than malignant tumors. Although benign tumors pose a lower health risk than malignant tumors, they both can be life-threatening in certain situations. There are many general characteristics which apply to either benign or malignant tumors, but sometimes one type may show characteristics of the other. For example, benign tumors are mostly well differentiated and malignant tumors are often undifferentiated. However, undifferentiated benign tumors and differentiated malignant tumors can occur.
Although benign tumors generally grow slowly, cases of fast-growing benign tumors have also been documented.
Some malignant tumors are mostly non-metastatic such as in the case of
basal-cell carcinoma.
CT and chest radiography can be a useful diagnostic exam in visualizing a benign tumor and differentiating it from a malignant tumor. The smaller the tumor on a radiograph, the more likely it is to be benign as 80% of lung nodules less than 2 cm in diameter are benign. Most benign nodules are smoothed radiopaque densities with clear margins but these are not exclusive signs of benign tumors.
Multistage carcinogenesis
Tumors are formed by
carcinogenesis
Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cell (biology), cells are malignant transformation, transformed into cancer cells. The process is characterized by changes at the cellular, G ...
, a process in which cellular alterations lead to the formation of cancer. Multistage carcinogenesis involves the sequential
genetic or
epigenetic changes to a cell's
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
, where each step produces a more advanced tumor. It is often broken down into three stages; initiation, promotion and progression, and several mutations may occur at each stage. Initiation is where the first genetic mutation occurs in a cell. Promotion is the clonal expansion (repeated division) of this transformed cell into a visible tumor that is usually benign. Following promotion, progression may take place where more genetic mutations are acquired in a sub-population of tumor cells. Progression changes the benign tumor into a malignant tumor.
A prominent and well studied example of this phenomenon is the tubular adenoma, a common type of
colon polyp which is an important precursor to colon cancer. The cells in tubular adenomas, like most tumors that frequently progress to cancer, show certain abnormalities of cell maturation and appearance collectively known as
dysplasia. These cellular abnormalities are not seen in benign tumors that rarely or never turn cancerous, but are seen in other pre-cancerous tissue abnormalities which do not form discrete masses, such as
pre-cancerous lesions of the uterine cervix.
Diagnosis
Classification
Benign
neoplasm
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 ...
s are typically, but not always, composed of cells which bear a strong resemblance to a normal cell type in their organ of origin. These tumors are named for the cell or tissue type from which they originate. The suffix "-oma" (but not -carcinoma, -sarcoma, or -blastoma, which are generally cancers) is applied to indicate a benign tumor. For example, a
lipoma
A lipoma is a benign tumor made of adipose tissue, fat tissue. They are generally soft to the touch, movable, and painless. They usually occur just under the skin, but occasionally may be deeper. Most are less than in size. Common locations inc ...
is a common benign tumor of fat cells (
lipocytes), and a
chondroma is a benign tumor of cartilage-forming cells (
chondrocytes).
Adenoma
An adenoma is a benign tumor of epithelium, epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organ (anatomy), organs, including the adrenal glands, pituitary gland, thyroid, prosta ...
s are benign tumors of gland-forming cells, and are usually specified further by their cell or organ of origin, as in
hepatic adenoma (a benign tumor of
hepatocyte
A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass.
These cells are involved in:
* Protein synthesis
* Protein storage
* Transformation of carbohydrates
* Synthesis of cholesterol, bi ...
s, or
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
cells).
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 ...
s contain many cell types such as skin, nerve, brain and thyroid, among others, because they are derived from germ cells.
Hamartomas are a group of benign tumors that have relatively normal
cellular differentiation
Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. Usually, the cell changes to a more specialized type. Differentiation happens multiple times during the development of a multicellula ...
but exhibit disorganized tissue organization.
Exceptions to the nomenclature rules exist for historical reasons; malignant examples include
melanoma
Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...
(a cancer of pigmented skin cells, or
melanocytes
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea),
the inner ear,
vaginal epithelium, meninges,
bones,
and hea ...
) and
seminoma
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a Malignancy, malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if di ...
(a cancer of male reproductive cells).
Benign tumors do not encompass all benign growths. Skin tags, vocal chord polyps, and hyperplastic polyps of the colon are often referred to as benign, but they are
overgrowths of normal tissue rather than neoplasms.
Treatment
Benign tumors typically need no treatment unless they cause problems such as seizures, discomfort or cosmetic concerns.
Surgery
Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...
is usually the most effective approach and is used to treat most benign tumors. In some cases, other treatments may be used. Adenomas of the
rectum
The rectum (: rectums or recta) is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. Before expulsion through the anus or cloaca, the rectum stores the feces temporarily. The adult ...
may be treated with
sclerotherapy, in which chemicals are used to shrink blood vessels in order to cut off the blood supply.
Most benign tumors do not respond to
chemotherapy
Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
or
radiation therapy
Radiation therapy or radiotherapy (RT, RTx, or XRT) is a therapy, treatment using ionizing radiation, generally provided as part of treatment of cancer, cancer therapy to either kill or control the growth of malignancy, malignant cell (biology), ...
, although there are exceptions; benign intercranial tumors are sometimes treated with radiation therapy and chemotherapy under certain circumstances.
Radiation can also be used to treat hemangiomas in the rectum.
Benign skin tumors are usually surgically resected but other treatments such as
cryotherapy
Cryotherapy, sometimes known as cold therapy, is the local or general use of low temperatures in medical therapy. Cryotherapy can be used in many ways, including whole body exposure for therapeutic health benefits or may be used locally to treat ...
,
curettage,
electrodesiccation,
laser therapy,
dermabrasion,
chemical peels
A chemical peel is a treatment used to improve and smooth the texture of the skin. The skin on the face is most commonly treated, but peels can also be performed on the body. Chemical peels are intended to remove the outermost layers of the skin ...
and
topical medication
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surface area, body surfaces such as the skin or mucous membranes to treat ailments via a large ...
are used.
References
{{Authority control
Medical terminology
Benign neoplasms