What Is Gorlin Cyst?
A Gorlin cyst or calcifying odontogenic cyst, is a cyst of dental origin. This is a rare developmental lesion of an odontogenic origin first documented by Gorlin et al. in 1962, hence the name. Later in 2005, WHO (World Health Organization) named this cyst a calcifying cystic odontogenic tumor (CCOT) after assessing its histological complexity, types, aggressiveness, or proliferative capacity to spread to the surrounding tissues locally.
Although the clinical features of this cyst are benign, as a pathologic entity, the lesion or cystic contents encompass a wide range of clinical behavior that varies from individual to individual. This cystic lesion exhibits a spectrum of histopathological patterns: cystic, solid, and aggressive. Considering the variable histopathological patterns and aggressive biological behavior, Gorlin's cyst was reclassified as an odontogenic tumor (neoplasm) in the 2005 WHO classification. The terms calcifying odontogenic cyst and calcifying odontogenic tumor have been used interchangeably, though the topic remains debatable.
Several authors have attempted to classify the Gorlin cyst based on its histopathological types. They have renamed this entity the calcifying ghost cell odontogenic cyst or dentinogenic ghost cell tumor, though the most commonly used terminology is CCOT.
What Is the Pathology of Gorlin Cyst?
It exhibits extreme diversity in its clinical and histopathological features, as well as in its biological behavior. A notable histopathological characteristic is the cystic lining with "ghost-cells" epithelial cells that tend to calcify. While its origin is linked to remnants of the dental lamina, recent evidence indicates that most COC cases carry a mutation in the CTNNB1 gene, which is responsible for the synthesis of the beta-catenin protein.
What Are the Symptoms of a Gorlin Cyst?
Symptoms of a Gorlin cyst can vary depending on its size and location but commonly include:
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Swelling: A noticeable swelling in the jaw or oral cavity.
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Pain: Discomfort or pain in the affected area, although some cysts may be asymptomatic.
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Tooth Displacement: Movement or loosening of adjacent teeth due to the cyst's growth.
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Jaw Expansion: Observable expansion of the jawbone.
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Delayed Tooth Eruption: In children, it may interfere with the normal eruption of teeth.
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Pus Discharge: In some cases, an infection may cause pus discharge.
It is important to note that Gorlin cysts can sometimes be asymptomatic and are discovered incidentally during routine dental examinations or radiographs. If the person experiences any of these symptoms, it is advisable to consult a dental or medical professional for a thorough evaluation and appropriate treatment.
What Are the Clinical Types of Gorlin Cyst?
The lesion or cyst clinically manifests either as
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Central variant (intraosseous).
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Peripheral variant (extraosseous).
Out of these variants, the central variant of the Gorlin cyst is more prevalent or often observed in clinical expression. Research shows these cysts occur over a broad age spectrum, from the first to the eighth decade of life. However, more cases were reported in the second decade of life in young adults, and the mean age group was between 20 and 30 years. This cyst affects both genders equally and without any distinct racial predilection.
Gorlin cysts represent up to nearly 2 % of all oral or odontogenic pathologies of the jaw bones. The characteristic clinical features of this cyst are -
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It is a painless and slow-growing lesion that may affect the upper (maxilla) and lower (mandible) jaw bones equally.
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The origin of the cyst tends to be intraosseous or within the bone, though extraosseous cysts can also occur.
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The anterior segment of the maxilla, or mandible, tends to be a common location for cyst occurrence.
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Teeth associated with the Gorlin cyst are commonly known to be affected by root resorption and divergence that can be detected radiographically by IOPA X-rays (intraoral periapical radiographs), OPG (orthopantomogram) or CBCT (cone-beam computed tomography systems - 2D or 3D imaging radiographic dental modalities).
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In most cases, this cyst is also found to be associated with an impacted tooth, which can predictably occur in up to one-third of Gorlin cyst cases.
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Asymptomatic swelling within the upper or lower jaw bone, most often anteriorly, is a common clinical feature with buccal or lingual cortical plate expansion.
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In both extraosseous and intraosseous lesions, the expansion of the buccal or lingual cortical plates is a confirmatory diagnosis when the cystic content and lesion are benign.
How Is Gorlin Cyst Diagnosed?
Radiographic Diagnosis -
Radiographically, the Gorlin cyst appears mainly as a unilocular or multilocular radiolucent mass or cystic lesion. This can either be well-circumscribed or poorly-defined. When observed in association with unerupted teeth, the dentist should consider the differential diagnosis of other odontogenic lesions, even though it is still possible for a Gorlin cyst to be associated with unerupted teeth. Calcification or calcified cystic regions, is an important and confirmatory radiographic diagnosis for the Gorlin cyst in nearly half of the reported or observed cyst cases in affected individuals.
Histopathologic Diagnosis -
The unique histopathological features of the Gorlin cyst include the components of a fibrous wall, with the cyst lined by odontogenic epithelium composed of cells that resemble ameloblast-like cells (tall columnar). Stellate reticulum-like cells usually overlap the basal cell layer with the ghost cells, hence the dentinogenic ghost cell tumor name. It may also show signs of calcification.
What Are the Treatment Strategies for Gorlin Cyst?
The treatment of choice for the Gorlin cyst is always a conservative surgical approach with a broad base enucleation that would prevent recurrence in cases of intraosseous lesions of the cyst. Surgical excision is preferred for the extraosseous form of the Gorlin cyst, and the long-term prognosis is excellent as the recurrence rates for this type are meager. Even though intraosseous Gorlin cysts have seemingly high recurrence rates, the prognosis and survival rates are better. Follow-up visits help track the development of recurrent lesions, if any.
Conclusion:
Thus, the Gorlin cyst is a challenging entity that presents as a cyst or benign tumor with probable malignant potential and is also associated with other lesions of odontogenic origin. However, prompt diagnosis and timely surgical resection of the cyst result in an excellent long-term prognosis. Surgical elimination of the cystic entity, followed by periodic assessment of the surgical site, is often advised to rule out the possibility of recurrences.
