|Year : 2020 | Volume
| Issue : 3 | Page : 138-141
Paradental cyst: Misdiagnosed or underdiagnosed
Department of Oral and Maxillofacial Pathology, ITS Dental College, Ghaziabad, Uttar Pradesh, India
|Date of Submission||05-Jun-2020|
|Date of Decision||07-May-2020|
|Date of Acceptance||27-May-2020|
|Date of Web Publication||08-Oct-2020|
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Source of Support: None, Conflict of Interest: None
Paradental cysts (PDCs) are odontogenic cysts having inflammatory origin contributing to 3%–5% of all odontogenic cysts. They arise either on the buccal, distal, or mesial aspects of partially erupted mandibular third molars. It has been previously known by various terms such as collateral inflammatory cyst, inflammatory lateral periodontal cyst, or mandibular infected buccal cyst. PDC is most commonly associated with recurrent history of pericoronitis and is attached to the cementoenamel junction and coronal third of the roots. While there is little doubt that it develops as a response to chronic inflammatory stimulus triggering proliferation of the crevicular and/or odontogenic epithelium, considerably same as other inflammatory odontogenic cysts, the exact histogenesis remains unclear. The PDC is commonly misinterpreted when it is associated with atypical characteristics clinically and radiographically, in turn causing diagnostic problems, leading to misdiagnosis as other inflammatory cysts including the dentigerous cyst of inflammatory origin. In this present case series, two cases with a history of pericoronitis are discussed showing overlapping clinical, radiographic, and histological features with other odontogenic cysts creating diagnostic dilemma. A combined correlation of all relevant findings helped to attain a final diagnosis of PDC.
Keywords: Cyst, inflammatory cyst, paradental
|How to cite this article:|
Verma F. Paradental cyst: Misdiagnosed or underdiagnosed. J Dent Res Rev 2020;7:138-41
| Introduction|| |
Paradental cyst (PDC) is a type of odontogenic cyst having inflammatory origin. It was first described by Craig in 1976. Inflammatory PDC has been reported by shear with four clinical variants, i.e., PDC, juvenile PDC, maxillary PDC, and premolar PDC with increased frequency of paradental variety in the mandibular third molar region (61%), followed by mandibular first/second molar (36%), globulomaxillary region (2.7%), and mandibular premolar (1%) region. The relatively low frequency of the PDC among all odontogenic cysts has been reported to be 3%–5% by shear and 4.7% by Craig,, while its exact prevalence is believed to be greater since several cases are misdiagnosed. Over the years, controversies regarding terminology have been reported and PDC has been addressed as “inflammatory collateral cyst” by Main, “mandibular infected buccal cyst,” “inflammatory lateral periodontal cyst,” “eruption pocket cyst” or “pericoronitis-associated eruption pocket cyst,” and “paradental and Hofarth's mandibular cyst“ by different authors.
Over 60% of PDCs are associated with mandibular third molars frequently associated with a history of recurrent or persistent pericoronitis. PDCs commonly appear on buccal aspects and rarely on the mesial aspect of partially or fully erupted teeth, whereas in impacted teeth, these are usually located on the mesial, buccal, or distobuccal aspects. Gender predilection in case series reported by Craig (1976) and Ackerman et al. (1987) suggests a considerable predominance of males., However, studies have shown an equal sex distribution, especially for the PDCs located in the first and second molar areas.
Clinically, concerned tooth is seen to be associated with inflammatory periodontal condition resulting from food impaction. Further food impaction may have an important part in the development of PDC. Radiographically, reported cases with attachment of cystic lining at the cementoenamel junction and its continuity with the oral epithelium are documented. PDC often appears as a well-demarcated unilocular radiolucency having corticated margins and is seen superimposed on the buccal side of the root surface. Histologically, it has a hyperplastic, nonkeratinized, stratified squamous epithelium lining which may be spongiotic in nature and of variable thickness. The connective tissue wall is infiltrated by mixed inflammatory cells including neutrophils, lymphocytes, and plasma cells. Similar clinicopathological correlation, however, is seen in various other lesions such as lateral periodontal cysts, odontogenic keratocysts, and small dentigerous cysts, making the diagnosis even more challenging.
The purpose of this study is, therefore, to present a series of two cases of PDC and discuss the need to refine the terminologies regarding the PDC.
| Case Report|| |
A 35-year-old female patient reported with a chief complaint of pain in her lower left back tooth region for 3 months. On intraoral examination, impacted left mandibular third molar was observed associated with pericoronitis. The radiographic evaluation revealed a well-circumscribed radiolucency with a smooth, regular outline attached to the crown portion of horizontally impacted third molar [Figure 1]a. Extraction along with associated lesion was done and sent for histopathological evaluation. Histopathological examination showed an overlying epithelium 2–4 cell layers thick arranged in arcading pattern. The cells in the lining epithelium appeared polygonal with large hyperchromatic round-to-oval-shaped nuclei. Underlying capsule had a dense irregular arrangement of collagen fibers with plasma lymphocytic infiltrate. Hemorrhagic areas were also evident [Figure 1]b. The clinicopathological features were suggestive of PDC.
|Figure 1: Orthopantomogram with radiolucency (black arrow) around crown of mesioangularly impacted third molar (a), Photomicrograph revealing cystic lining with diffusely infiltrated mixed inflammatory infiltrate (b) (H and E, ×100)|
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A 31-year-old male patient reported with the chief complaint of having pain and swelling in the right lower back tooth region for 2 months. On clinical examination, the swelling appeared in relation to the right mandibular angle region and produced marked facial asymmetry on the right side. Radiographic examination showed a radio-lucent area on the distal aspect of the right mandibular third molar. The tooth was vertically impacted [Figure 2]a. Extraction was done along with the associated lesion. Gross examination revealed a creamish brown, smooth-surfaced lesion attached to the distal surface of the extracted tooth specimen [Figure 2]b. The cystic lesion was dissected, and lumen was examined under a stereomicroscope, which revealed a well-defined cystic cavity lined by a dense fibrous capsule, showing numerous nodular projections into the lumen [Figure 2]c. On histopathological evaluation, cystic lining was hyperplastic in nature and composed of nonkeratinized stratified squamous epithelium seen in arcades. Within these arcades, large hemorrhagic areas and neutrophils were evident. The epithelial cells appeared to be large, polygonal in shape with hyperchromatic nuclei. The connective tissue showed juxtaepithelial aggregation of plasma cells and lymphocytes. Underlying capsule was devoid of inflammation [Figure 2]d. The overall clinicopathological features were suggestive of PDC.
|Figure 2: Orthopantomogram with vertically impacted 48 and radiolucency on the distal side (black arrow) (a), Extracted 48 with cystic pathology attached on the distal aspect (b), Stereomicroscopic appearance of lumen with nodularity on the inner aspect (c), Photomicrograph with cystic lining thrown into folds and inflamed capsule (d) (H and E, ×100)|
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| Discussion|| |
PDC has been known by various names including “inflammatory collateral cyst,” “mandibular infected buccal cyst,” “mandibular buccal bifurcation cyst,” “inflammatory lateral periodontal cyst,” and “inflammatory PDC” as discussed by Chrcanovic et al., PDCs are a rare type of odontogenic cyst, in terms of their relative occurrence PDC was first included in the World Health Organization histological type of odontogenic tumors in 1992., A new characterization of this cyst can add as a contributing factor to its nonrecognition. Conversely, it has been considered that this lesion has been underdiagnosed or misdiagnosed as dentigerous cyst, lateral radicular cyst, pericoronitis, lateral periodontal cyst, odontogenic keratocyst, or some other entities related to the inflammatory conditions of the dental follicle. Another fact that could result in the underdiagnosis of PDCs is that histopathological analysis of extirpated follicular sacs is rarely done.
The etiology of PDCs is of an inflammatory nature, as shown by the histological findings of odontogenic epithelium proliferation, presence of an inflammatory infiltrate, and occasional hyaline changes in blood vessel walls. Disagreement with regard to pathogenesis of the cyst left the PDC unclarified. Although the histogenesis of PDC is still obscure, there might be these three potential elucidations for the development of PDC. (a) Crevicular epithelium origin: Association between cyst epithelial lining and crevicular epithelium has been reported. This could occur due to local destruction of the periodontium resulting in a deep pocket formation. It further dilates and develops into a cystic lesion as tissues in the third molar area are loose nature and presence of obstruction to the pocket opening. This cascade is followed by a secondary event, crevicular epithelium proliferation. (b) Result of proliferating cell rests of Malassez: Pericoronitis may lead to gingival extension due to inflammatory response. However, this mechanism cannot be completely excluded, but it appears unlikely to occur. (c) Reduced enamel epithelium (REE) origin: Induced proliferation of remnants of REE is present on the surface of enamel spur in the root furcation area and further may endure cystic degeneration triggered by chronic as well as intermittent inflammation. This is mainly true in cases of subcomponent of PDCs which are known as “infected buccal bifurcation cysts.” It has been reported that small projections of enamel are present within the root bifurcation area on the buccal aspect of the teeth, known as enamel pearls. They act as a stagnation region due to the accumulation and growth of bacterial-infected dental plaque, facilitating the development of periodontal breakdown and localized bone destruction, subsequently instigating the development of a cyst.,
Fowler and Brannon discussed about “lateral periodontal cyst” having clinical and radiographic similarity to PDC, while the origin appears to be developmental rather than inflammatory. They also speculated that PDC may be a variant of dentigerous cyst or may arise from “occluded periodontal pocket.”
A survey from literature showed that Hofarth in 1930 reported numerous cases of jaw cysts present on the distal aspect of mandibular third molars showing clinical signs of pericoronitis. It was named as “marginal wisdom tooth cyst.” Mufeed A et al., stated that criteria to define a paradental cyst in clinical, radiological as well as histological aspect is justified by the description given by Hofarth. In the present cases, the cyst was associated with lateral aspect and crown area of impacted tooth. The teeth involved were vital, these features excludes the possibility of radicular cyst in such a location.
Colgan et al. proposed the importance of a preserved follicular space (which is not part of cyst formation) seen surrounding the involved tooth on radiographs, stated as Colgan's sign, to be a diagnostic aid when in dilemma to differentiate between paradental or dentigerous cysts. On the other side, Chrcanovic et al. mentioned that identical etiology, as well as histology, in the inflammatory collateral cyst, the PDC, and the mandibular infected buccal cyst is seen while contradictory clinical and radiology appearance could be due to type of tooth involved and eruption time. The confusion still remains regarding these three lesions which are considered to be the same irrespective of the location.
Colgan et al. reported in their case series a remarkable association considering the impaction angle of involved tooth and location of the cyst, which might be related to its pathogenicity. They also proposed a possible role of food impaction in pathogenesis, elucidating that direction of deflection of food into the gingival tissues will be a dependent impaction angle. Impaction in mesioangular direction will force food toward the distal surface. Conversely, impaction in vertical, distoangular, and less acute mesioangular direction will deflect food in buccal and distal or distobuccal aspects. In our first case, mesial angular impaction having cyst development on the distal aspect of the second molar was seen while the second case showed vertical impaction with cystic lesion present on the distobuccal aspect, similar to the proposed relationship.
Histological appearances of PDCs described by other authors are similar to those seen in our cases showing hyperplastic stratified squamous epithelial lining usually nonkeratinized and spongiotic in nature. They defined the fibrovascular connective tissue comprising intense chronic or mixed inflammatory cells., Magnusson and Borrman conducted a clinicopathological study consisting of 26 cases of PDCs, histopathologically showing nonkeratinized stratified squamous epithelium immigrated with neutrophils. In most cases, the epithelium showed marked hyperplasia with mixed infiltration of connective tissue wall by neutrophils, lymphocytes, and plasma cells, which appears to be similar in our cases.
Vedtofte and Praetorius, stated that PDC originates in cases associated with pericoronitis, we agree with their suggestion, as both of the present cases were associated with history of pericoronitis. Treatment modality would include complete removal of cystic lesion along with extraction of involved tooth in case of third molars, whereas preservation of tooth in cases of first and second molars. Thus, the study of the present two cases showed that combined emphasis should be given on clinical as well as pathological aspects while reporting such lesions. On the other hand, including stereomicroscopic examination to detect these lesions, may give some new findings. cyst of one case under stereomicroscope showing thicken cystic wall with nodularity on the inner surface, reflecting the hyperplastic areas.
| Conclusion|| |
One of the characteristic features of PDC noticed clinically was associated with mandibular molars, showing the limited distribution of this lesion with well-defined radiolucency on radiographs. Further, stereomicroscopic assessment of the cyst would add to new findings. The controversies regarding the various terminologies used for this entity are due to its various clinical presentations and have always been a question of debate. As there appears to be no specific histopathological or clinical feature to describe this lesion, a combined clinicopathological assessment is essential to reach a diagnosis of PDC.
Declaration of patient consent
Information related to patients has been obtained only after receiving his/her consent for images and radiographs to be used for research/study purpose.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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