SRM Journal of Research in Dental Sciences

CASE REPORT
Year
: 2020  |  Volume : 11  |  Issue : 4  |  Page : 229--232

Case report of a dentigerous cyst with mucous prosoplasia: As an incidental finding


Nimoshini Gowrinathan, C Hima Bindu Reddy, ZH Husna Sofia, R Jemima, Jeslyn Jeromy, N Vaishnavi Dhanvantri 
 Department of Oral Pathology, SRM Dental College and Hospital, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. N Vaishnavi Dhanvantri
Department of Oral Pathology, SRM Dental College and Hospital, Chennai, Tamil Nadu
India

Abstract

Dentigerous cysts, also called follicular cysts, are developmental odontogenic cysts that occur in association with an unerupted tooth. Fluid accumulation between the enamel epithelium and enamel causes the dental follicle to separate from the crown, giving rise to such cysts. Usually, these cysts do not show any symptoms and are diagnosed during routine radiological examination. Mucous cell prosoplasia is a rare type of entity commonly seen in oral pathologies such as odontogenic cysts and might lead to diagnostic difficulties. Although mucous cell prosoplasia is considered as a harmless condition, some studies have suggested that it may be a maiden step toward malignant transformation. We report a case of the dentigerous cyst with mucous prosoplasia that presented as an incidental finding emphasizing the importance of radiographs and histopathology in the definitive diagnosis of such cases.



How to cite this article:
Gowrinathan N, Bindu Reddy C H, Husna Sofia Z H, Jemima R, Jeromy J, Dhanvantri N V. Case report of a dentigerous cyst with mucous prosoplasia: As an incidental finding.SRM J Res Dent Sci 2020;11:229-232


How to cite this URL:
Gowrinathan N, Bindu Reddy C H, Husna Sofia Z H, Jemima R, Jeromy J, Dhanvantri N V. Case report of a dentigerous cyst with mucous prosoplasia: As an incidental finding. SRM J Res Dent Sci [serial online] 2020 [cited 2021 Apr 15 ];11:229-232
Available from: https://www.srmjrds.in/text.asp?2020/11/4/229/308782


Full Text

 Introduction



Among the odontogenic cysts, dentigerous cysts are considered the most common developmental cysts. They are found in association with embedded, unerupted, or impacted permanent tooth crown.[1],[2] They are frequently found in relation to mandibular third molars. They usually do not present with any alarming symptoms and are discovered accidentally or incidentally on radiographs (as radiolucencies), generally taken for investigation of tooth eruption delay or other general dental treatments. These cysts may become symptomatic if infected and may increase in size causing displacement of teeth and bone expansion.[3]

Radiographically, dentigerous cysts appear as simple well-defined, radiolucent lesions with sclerotic borders associated with an unerupted tooth and surrounded by a cystic space exceeding 5 mm3. However, large cysts may show a multilocular feature causing diagnostic difficulties. Histologically, they show a cystic cavity that is lined by 2-3 layered, thin nonkeratinizing epithelium that is devoid of rete pegs, having a fibrous wall without inflammatory cells. Enucleation and extraction of the associated tooth is the preferred treatment option.[3],[4]

Prosoplasia is the forward cellular differentiation, into cells with an intricate or higher function with a complex level of organization. In mucous cell prosoplasia, a simple squamous epithelial cell differentiates and transforms into a mucous secreting cell. It is a rare type of entity commonly seen in oral pathologies such as odontogenic cysts including dentigerous cysts and might lead to diagnostic difficulties. Although mucous cell prosoplasia is considered as a harmless condition, some studies have suggested that it may be a maiden step toward malignant transformation.[5]

Here, we report a case of the dentigerous cyst with mucous prosoplasia that presented as an incidental finding.

 Case Report



A 44-year-old male patient reported to the department for general dental checkup. The patient had a known medical history of schizophrenia for the past 20 years and was under medications for the same. Apart from several missing teeth including 38, the clinical examination revealed no obvious relevant extraoral or intraoral findings [Figure 1]a and [Figure 1]b.{Figure 1}

Routine radiographic examination revealed an unilocular radiolucency that was well-circumscribed and involved the crown of impacted 38 [Figure 2]. It was found extending to 37 regions and to the inferior border of the mandible. A preoperative diagnosis was given as dentigerous cyst. The cyst enucleation with the extraction of the impacted wisdom teeth was done under local anesthesia. The postoperative follow-up was uneventful. The patient was advised to follow-up every 6 months.{Figure 2}

The enucleated specimens were sent for histopathological diagnosis. Macroscopically, the soft-tissue specimens were firm inconsistency. The superior surface was creamy white in color and the inferior surface was brownishred in color. Microscopic examination revealed a cystic cavity that was lined by the stratified squamous epithelium of varied thickness. The epithelium was made up of nonkeratinized stratified squamous epithelium and was 2–4 layers thick [Figure 3]a and [Figure 3]b. In a few areas, the epithelium was hyperplastic. The epithelium showed mucous cells in areas with increased proliferative activity suggestive of mucous prosoplasia [Figure 3]c and [Figure 3]d. The connective tissue was dense collagenous in nature with numerous chronic inflammatory cells. The connective tissue also showed numerous extravasated red blood cells and cholesterol clefts along with few hemosiderin pigments. With the above mentioned features, a diagnosis of the dentigerous cyst with mucous prosoplasia was given.{Figure 3}

Based on the radiographic and microscopic features, the final diagnosis was established as dentigerous cyst with mucous prosoplasia.

 Discussion



Dentigerous cysts arise when fluid or inflammatory exudates accumulate between the crown of an unerupted tooth and the reduced enamel epithelium. The hydrostatic pressure of their content causes unicentric expansion and enlargement of such cysts. These can cause lingual and buccal expansions that are seen clinically.[1],[2]

Radiographically, a well-demarcated unilocular radiolucent lesion that is attached to the unerupted tooth (cervical area) with well-defined margins and sclerotic borders is seen in dentigerous cysts. During the radiographic examination, a dentigerous cyst and a normal dental follicle are differentiated only based on size (a cystic space exceeding 5 mm3- dentigerous cyst to be suspected). However, multilocular radiolucencies may be seen in large cysts and ill-defined margins are seen in infected cysts, causing diagnostic difficulties.[6] In this case, the typical well-circumscribed unilocular radiolucency of the dentigerous cyst, was present in relation to 38, that aided us in the incidental clinical diagnosis, even in the absence of clinical symptoms, or signs.

Histopathologically, the cystic spaces of these cysts are lined by a thin nonkeratinized 2-3 layered epithelium, resembling a thin reduced enamel epithelium-like lining. Dentigerous cysts have more potential for growth, differentiation, and degeneration than other cysts such as inflammatory cysts or radicular cysts as they are developmental in origin and develop from the follicular epithelium. There is a possibility that malignant carcinomas like mucoepidermoid carcinoma can arise from these cysts due to their differentiation potential. Pathological fractures of jaw bones may also occur due to their tendency to expand rapidly.[6] Thus, definitive diagnosis and prompt treatment for these cysts are essential and are of clinical significance. In the present case, typical histopathological features of dentigerous cysts were present along with mucous prosoplasia.

Mucous cell prosoplasia though it is a rare event in odontogenic lesions, it is significant because it presents overlapping histopathological features with various other conditions. Hence, a better understanding of such prosoplasia can aid in the diagnosis.[7] Odontogenic cysts comprising radicular cysts, residual cysts, dentigerous cysts, odontogenic keratocyst, and ameloblastomas may show mucous cell prosoplasia.[5] An association between the age of the cystic lining and mucous cell prosoplasia has been found in previous studies; wherein with increasing age of the patient, the occurrence of mucous cells in dentigerous cysts also showed an increasing trend.[8] In this case, the patient was in his fourth decade, which could be the reason for the mucous prosoplasia development.

In a case report by Kochaji et al., the dentigerous cyst that was left untreated for 10 years, gave rise to mucoepidermoid carcinoma in the region causing destruction of the maxillary sinus. As a result, the patient had to undergo hemimaxillectomy and undergo radiotherapy for 6 months.[9] Such cases call attention to the importance of identification of such dentigerous cysts with mucous prosoplasia and to the need for prompt treatment, as neoplastic transformation of the cystic lining is a possibility.[9],[10]

Further research is needed to find the exact mechanism for the occurrence of mucous cell prosoplasia and how it contributes to malignant transformation. A study by Prokopis et al. suggested that molecular events such as mastermind-like 2 rearrangements that are considered diagnostic for mucoepidermoid carcinoma are found on dentigerous cysts with mucous prosoplasia.[10] Such findings indicate that mucous prosoplasia in odontogenic cysts may be a precursor or intermediate stage in the malignant transformation.

 Conclusion



Thus, mucous prosoplasia in dentigerous cysts maybe considered as a maiden step toward neoplastic transformation and treatment should be initiated promptly with sufficient follow-up. In asymptomatic cases such as our present case, radiographic and histopathological examinations hold a key role in definitive diagnosis and to determine treatment options and prognosis.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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