Odontogenic keratocyst
Encyclopedia
A keratocystic odontogenic tumour (also keratocystic odontogenic tumor), abbreviated KCOT, is a rare and benign
but locally aggressive developmental cyst
ic neoplasm. It most often affects the posterior mandible.
It was previously called odontogenic keratocyst and abbreviated OKC.
and examination under the microscope.
Under the microscope
, KCOTs vaguely resemble keratinized squamous epithelium
; however, they
and associated with impacted teeth. Multiple odontogenic keratocysts are a feature of nevoid basal cell carcinoma syndrome
.
Odotogenic Keratocysts are derived from the Remnants of the Dental Lamina.
KCOTs are associated with mutations in the gene
PTCH
, which is part of the Hedgehog signaling pathway
.
to squamous cell carcinoma
may occur, but is unusual.
Treatment options:
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
but locally aggressive developmental cyst
Cyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
ic neoplasm. It most often affects the posterior mandible.
It was previously called odontogenic keratocyst and abbreviated OKC.
Diagnosis
The definitive diagnosis is by histologic analysis, i.e. excisionExcision
Excision is the alias of Jeff Abel, a dubstep DJ and music boss from British Columbia, Canada. He frequently works with fellow Canadian dubstep producers Datsik and Downlink. As one of the first dubstep producers and DJs in North America, he has played a significant role in the genre's growth in...
and examination under the microscope.
Under the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
, KCOTs vaguely resemble keratinized squamous epithelium
Squamous epithelium
In anatomy, squamous epithelium is an epithelium characterised by its most superficial layer consisting of flat, scale-like cells called squamous epithelial cells...
; however, they
- lack rete ridges and
- often have an artifactual separation from their basement membraneBasement membraneThe basement membrane is a thin sheet of fibers that underlies the epithelium, which lines the cavities and surfaces of organs including skin, or the endothelium, which lines the interior surface of blood vessels.- Composition :...
.
Etiology
KCOTs are thought to arise from the dental laminaDental lamina
The dental lamina is a band of epithelial tissue seen in histologic sections of a developing tooth. The dental lamina is first evidence of tooth development and begins at the sixth week in utero or three weeks after the rupture of the buccopharyngeal membrane. It is formed when cells of the oral...
and associated with impacted teeth. Multiple odontogenic keratocysts are a feature of nevoid basal cell carcinoma syndrome
Nevoid basal cell carcinoma syndrome
Nevoid basal cell carcinoma syndrome , also known as basal cell nevus syndrome, multiple basal cell carcinoma syndrome, Gorlin syndrome, and Gorlin–Goltz syndrome, is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine...
.
Odotogenic Keratocysts are derived from the Remnants of the Dental Lamina.
Genetics
Sporadic (non-syndromic) and syndromicSyndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
KCOTs are associated with mutations in the gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
PTCH
PTCH1
Protein patched homolog 1 is a protein that is the member of the Patched family and in humans is encoded by the PTCH1 gene.- Function :PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in...
, which is part of the Hedgehog signaling pathway
Hedgehog signaling pathway
In a growing embryo, cells develop differently in the head or tail end of the embryo, the left or right, and other positions. They also form segments which develop into different body parts. The hedgehog signaling pathway gives cells information that they need to make the embryo develop properly....
.
Symptoms
Swelling is the most common presenting complaint; however, KCOTs may be asymptomatic and found incidentally on dental X-rays.Differential diagnosis
- Odontogenic cystPeriapical cystThe periapical cyst is the most common odontogenic cyst. It is caused by pulpal necrosis secondary to dental caries or trauma. The cyst lining is derived from the cell rests of Malassez. Usually, the periapical cyst is asymptomatic, but a secondary infection can cause pain...
(histologically) - Dentigerous cystDentigerous CystA dentigerous cyst or Follicular Cyst is an odontogenic cyst - thought to be of developmental origin - associated with the crown of an unerupted tooth. The cyst cavity is lined by epithelial cells derived from the reduced enamel epithelium of the tooth forming organ...
- AmeloblastomaAmeloblastomaAmeloblastoma is a rare, benign tumor of odontogenic epithelium much more commonly appearing in the lower jaw than the upper jaw. It was recognized in 1827 by Cusack...
(radiologically)
Malignant transformation
Malignant transformationMalignant transformation
Malignant transformation is the process by which cells acquire the properties of cancer. This may occur as a primary process in normal tissue, or secondarily as malignant degeneration of a previously existing benign tumor....
to squamous cell carcinoma
Squamous cell carcinoma
Squamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...
may occur, but is unusual.
Treatment
As the entity is quite rare, opinions among experts about how to treat KCOTs differ.Treatment options:
- Wide (local) surgicalSurgerySurgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
excision. - MarsupializationMarsupializationMarsupialization is the surgical technique of cutting a slit into a cyst and suturing the edges of the slit to form a continuous surface from the exterior to the interior of the cyst. Sutured in this fashion, the cyst remains open and can drain freely...
- the surgical opening of the (KCOT) cavity and a creation of a marsupialMarsupialMarsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
-like pouchPouch (marsupial)The pouch is a distinguishing feature of female marsupials ; the name marsupial is derived from the Latin marsupium, meaning "pouch". Marsupials give birth to a live but relatively undeveloped fetus called a joey. When the joey is born it crawls from inside the mother to the pouch...
, so that the cavity is in contact with the outside for an extended period, e.g. three months. - CurettageCurettageCurettage, in medical procedures, is the use of a curette to remove tissue by scraping or scooping.Curettages are also a declining method of abortion. It has been replaced by vacuum aspiration over the last decade....
(simple excision & scrape-out of cavity). - Simple excision.
- Carnoy's solutionCarnoy's solutionCarnoy's solution is a fixative composed of 60% ethanol, 30% chloroform and 10% glacial acetic acid.Carnoy's Solution is composed of:*1 g of ferric chloride dissolved in 24 mL of absolute alcohol*12 mL of chloroform*4 mL of glacial acetic acid...
- usually used in conjunction with excision. - Enucleation and cryotherapy
External links
- Odontogenic keratocyst - pathconsultddx.com.