Central mucoepidermoid carcinoma arising from glandular odontogenic cyst confirmed by analysis of MAML2 rearrangement: A case report

Rare Histologic Imitator Central Mucoepidermoid Carcinoma Arising from Glandular Odontogenic Cyst of the Mandible: Case Report with Updated Review of Literature

Central mucoepidermoid carcinoma is a relatively rare salivary gland tumour of the jawbone. Glandular odontogenic cyst is another unique odontogenic developmental cyst characterised by glandular differentiation. Both entities share several histological characteristics, and a pre-existing Glandular odontogenic cyst can evolve into Central mucoepidermoid carcinoma. Case 1: A 56-year-old male presented with chief complaint of swelling in lower left facial region since 1 year. Histopathology revealed multicystic compartments resembling mucoepidermoid carcinoma, but strong positive expression of Cytokeratin 13 upon immunohistochemistry helped us in rendering the final diagnosis as Glandular odontogenic cyst Case 2: A 34-year-old female presented with a lesion on right side of face. Histologically, the biopsy specimen revealed both typical findings of a Glandular odontogenic cyst component and a recognizable component of Mucoepidermoid carcinoma. The results from cytokeratin profiling demonstrated that, while both Mucoepidermoid carcinoma and Glandular odontogenic cyst expressed Cyokeratins 7, 18, and 19. Cytokeratin 13 was interestingly exclusively expressed in Glandular odontogenic cyst. Present case findings showed that central mucoepidermoid carcinoma and Glandular odontogenic cyst may be part of the same disease spectrum. However, because the expression profile of Cytokeratin13 in mucoepidermoid carcinoma and Glandular odontogenic cyst was so diverse, it can be used to differentiate both.

Glandular Odontogenic Cyst: a Case Report and Literature Review

Background

The glandular odontogenic cyst is now a well-known entity comprising < 0.5% of all odontogenic cysts with a recent review tabulating about 200 cases in the English literature. Glandular odontogenic cyst shows epithelial features that simulate salivary gland or glandular differentiation. The importance of glandular odontogenic cyst relates to the fact that it has a high recurrence rate and shares overlapping histologic features with central mucoepidermoid carcinoma. The purpose of this paper is to describe the clinical, radiological, and histopathological features of a case of glandular odontogenic cyst with the course of treatment and 9-years follow-up, followed by a review of the literature.

Methods

A 63-year-old male was referred for further investigation of a mandibular radiolucency observed by his general dental practitioner. The main complaint was a murmuring sensation in the lower jaw right side. Radiological examination revealed a well-defined, unilocular, radiolucent lesion, involving the right mandible with 17 and 68 mm in mediolaterally and anteroposterior dimension, respectively.

Results

A total enucleation of the cystic lesion and surgical extraction of tooth #46, #47 and #48, was performed under local anaesthesia. Histopathologic examination revealed a glandular odontogenic cyst.

Conclusions

Glandular odontogenic cyst shows no pathognomonic clinico-radiographic characteristics, and therefore in many cases it resembles a wide spectrum of lesions. Diagnosis can be extremely difficult due to histopathological similarities with dentigerous cyst, lateral periodontal cyst and central mucoepidermoid carcinoma. Therefore a careful histopathological examination and a long-term follow-up (preferably seven years) are required to rule out recurrences.

Diagnostic Reliability of CRTC1/3::MAML2 Gene Fusion Transcripts in Discriminating Histologically Similar Intraosseous Mucoepidermoid Carcinoma from Glandular Odontogenic Cyst: A Systematic Review and Meta-analysis

BACKGROUND

Intraosseous mucoepidermoid carcinoma (IMEC) and Glandular odontogenic cyst (GOC) are those two pathological entities causing diagnostic dilemma due to the histopathological similarity. An accurate distinction between the two entities is difficult as both presents with a common radiological and histological similarities. The aim of our systematic review was to establish the diagnostic reliability of CRTC1/3::MAML2 gene fusion for the distinction between IMEC and GOC.

METHODS

A complete electronic literature search was made in MEDLINE by PubMed, Google Scholar, and EMBASE databases. Articles with keywords using molecular genetic findings of CRTC1/3::MAML2 gene fusion transcripts, IMEC and GOC were assessed and included for the systematic review.

RESULTS

Twelve subgroups having both qualitative and quantitative analysis revealed CRTC1/3::MAML2 sensitivity of 100% and specificity of 70.59% in differentiating GOC and IMEC. Fixed-effects model confirmed translocation-negative cases to have a decreased risk of association with IMEC (combined odds ratio 8.770, 95% confidence interval - 2.45 to 31.45, p < 0.002).

CONCLUSIONS

The current evidence supports that in all cases with positive gene fusion transcript of the CRTC1/3::MAML2 was specific for IMEC and was significantly differentiating it from GOC. Whereas cases of IMEC with negative gene fusion transcript pose diagnostic difficulty in differentiating from a GOC which is negative for CRTC1/3::MAML2 expression.

Transformation of Odontogenic Cysts to Neoplasms - A Systematic Review

Background

Odontogenic cysts have the potential to transform into neoplasms. However, the characteristics of those which transformed to neoplastic tissues have not been well described and the exact causes of that phenomenon are not yet clear.

Objectives

This study aims to describe characteristics of odontogenic cysts that transformed into neoplasms and to look for their potential etiologies.

Data Sources

English-written studies indexed in PubMed, Science Direct, and Proquest were assessed using keywords verified by Medical Subject Headings: 'Odontogenic Cyst' and 'Neoplastic Cell Transformation'.

Study Eligibility Criteria

Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines were used as guidance.

Participants

Following steps in PRISMA guidelines, 19 articles were fully reviewed (three case series and 16 case reports) with 27 subjects of 16 males (59%) and 11 females (41%) from 15 to 86 years old.

Results

Cystic origins were eight dentigerous cysts, four odontogenic keratocysts, two residual cysts, one radicular cyst, one calcifying odontogenic cyst, one follicular cyst, one glandular odontogenic cyst, and nine unspecified odontogenic cysts that transformed to ameloblastoma (3 cases) and carcinoma (24 cases).

Limitations

Neoplastic transformations of odontogenic cysts arose from epithelial remnants of inadequate odontogenic cyst removal and chronic inflammation due to infection. However, the exact causes of their transformations remain unclear.

Conclusions

Therefore, careful removal of odontogenic cysts and regular postoperative follow-ups are key to prevent recurrence and neoplastic transformation. Future studies are needed to investigate potential causes of neoplastic transformation of odontogenic cysts.

MAML2-Rearranged Primary Central Mucoepidermoid Carcinoma of the Mandible as an Incidental Finding: A Case Report and Review of the Literature of Molecularly Confirmed Cases

This report presents an extremely rare case of MAML2-rearranged primary central mucoepidermoid carcinoma (MEC) of the mandible that was discovered as an incidental finding. Our review of the literature identified 36 cases of MAML2-rearranged intraosseous lesions of the jaw (30 central MECs, 5 odontogenic cysts with mucous prosoplasia, and 1 glandular odontogenic cyst). Given the therapeutic indications for a diagnosis of MEC (a malignant neoplasm), MAML2 rearrangement should be confirmed in suspected cases of central MEC.

Clinical and radiologic spectrum of glandular odontogenic cysts: A multicenter study of 92 cases

OBJECTIVE

The purpose of this multicenter retrospective study was to report the clinical and radiologic features of 92 glandular odontogenic cysts (GOCs) diagnosed over a 20-year period.

STUDY DESIGN

Histologically confirmed cases of GOC were retrospectively reviewed from 4 oral pathology laboratories in South Africa and Brazil to categorize the clinical and radiologic spectrum of GOCs.

RESULTS

The mean age of patients was 46 years (range 17-87) with a male-to-female ratio of 1.2:1. GOCs had a mandibular predilection (68%), with 42% of all cases located anteriorly. Additionally, 42% of cases crossed the midline. Radiologically, most lesions were unilocular (53%) and uniformly radiolucent (97%), with well-demarcated borders (93%). Cortical expansion (62%), loss of cortical integrity (71%), and maxillary sinus (67%) and nasal cavity encroachment (72%) were common findings. Significant differences in lesions between the 2 countries were discovered in sex predilection, clinical signs and symptoms, and lesion locations within the mandible and maxilla.

CONCLUSION

GOCs present with a wide spectrum of clinical and radiologic features, ranging from cysts with typical GOC-like presentations to more aggressive lesions. The need for advanced imaging in the surgical planning of GOCs exhibiting radiologic signs of aggression is justified based on the high recurrence rate.

Central mucoepidermoid carcinoma arising directly from a glandular odontogenic cyst of the mandible: a case report

BACKGROUND

Central mucoepidermoid carcinoma (MEC) is a rare salivary gland tumor that affects the jawbone. Glandular odontogenic cyst (GOC) is also a rare odontogenic developmental cyst with glandular differentiation. GOC shares some histological features with central MEC, and a pre-existing GOC can develop into central MEC. Here, we present a rare case of central MEC developed directly from a pre-existing GOC of the mandible.

CASE PRESENTATION

A 67-year-old Japanese man presented with a cystic lesion in the right third molar region. Histologically, the biopsy specimen demonstrated both typical findings of a GOC component lined with non-keratinized squamous epithelium and a recognizable component of central MEC consisting of polycystic nests with mucous cells, intermediate cells, and epidermoid cells in the cyst wall. The results from the immunohistochemistry for cytokeratin (CK) profiling demonstrated that, while both central MEC and GOC expressed CKs 7, 14, 18, and 19, CK13 was interestingly exclusively expressed in GOC. Fluorescence in-situ hybridization (FISH) revealed the rearrangement of the Mastermind like (MAML)-2 gene in both the MEC and GOC components.

CONCLUSIONS

Our case suggests that central MEC and GOC may be in the same spectrum of diseases caused by the rearrangement of the MAML-2 gene. However, given that the expression profile of CK13 was completely different between central MEC and GOC, they can be considered as separate tumors. Overall, we demonstrated a rare case in which central MEC may have originated directly from the GOC.

Unique case of glandular odontogenic cyst showing mucoepidermoid carcinoma-like islands in cystic wall

Glandular odontogenic cyst (GOC) is a very rare jaw cyst accounting for 0.2% of all odontogenic cysts. It presents usually in adults with a slight male predominance. It shows radiological, histopathological and even immunohistochemical overlap with low grade intraosseous mucoepidermoid carcinoma (MEC) but their distinction is crucial. A 57-year-old woman with bilocular radiolucency in the anterior mandible crossing the midline is described here. Microscopy features were consistent with glandular odontogenic cyst but multiple MEC-like islands were seen in the capsule, creating a diagnostic head trip with low grade intraosseous MEC. However, the absence of cellular atypia and epidermoid and intermediate cells led to a final diagnosis of GOC, with close follow-up of the patient recommended. This rare finding shows the relation between GOC and MEC or the origin of MEC from GOC.

Dentigerous cyst exhibiting prominent mucous cell metaplasia: report of a unique case mimicking central mucoepidermoid carcinoma

A Japanese male aged 61 presented with persistent pain in the left posterior area of the mandible for several weeks. A panoramic X-ray revealed a unilocular lesion showing characteristics of a dentigerous cyst associated with an impacted third molar. A cystectomy was performed and histopathological examination revealed a cystic lesion with a fibrous wall. The lumen was covered with non-keratinizing squamous cells with obvious intercellular bridges, which were intermingled with partially ciliated goblet-cell-type mucous and columnar cells. Such cystic lesions should be carefully examined to distinguish them from the glandular odontogenic cyst and central mucoepidermoid carcinoma of the jawbone.

Glandular Odontogenic Cyst-A Case Series

The glandular odontogenic cyst (GOC) is an uncommon jawbone cyst with a challenging diagnosis because of the presence of several clinical and histopathologic overlaps with other odontogenic lesions and central mucoepidermoid carcinoma. To date, less than 200 cases of GOC have been published in the literature with reliable clinical and histopathologic information. Furthermore, the lack of a well-documented GOC case series impairs a more detailed understanding about the biological behavior and appropriate management of the lesion. Therefore, in this study, we report 3 well-documented cases of GOC in the literature. In one of the cases, the incisional biopsy was misdiagnosed as a dentigerous cyst, and the lesion recurred. Therefore, we also discuss key points regarding the diagnosis and treatment of GOC.

The reliability of MAML2 gene rearrangement in discriminating between histologically similar glandular odontogenic cysts and intraosseous mucoepidermoid carcinomas

OBJECTIVE

MAML2 expression is proven in the majority of mucoepidermoid carcinomas (MECs) arising in salivary glands. MEC can also occur intraosseously (IMEC). Glandular odontogenic cyst (GOC) is an odontogenic cyst with histologic overlap with IMEC. This study aimed to determine the reliability of MAML2 in distinguishing IMEC cases from GOC cases.

STUDY DESIGN

An institutional review board-approved retrospective search of IMEC, GOC, and IMEC with prior history of GOC was performed within the archives of the University of Florida and the University of Alberta Oral Pathology Biopsy Services. Nine cases from 5 patients were selected. Break-apart fluorescent in situ hybridization analysis was performed on 7 cases for the presence of MAML2 rearrangement.

RESULTS

Four cases had negative MAML2 gene rearrangement, and 3 cases had positive MAML2 gene rearrangement.

CONCLUSIONS

Although it can be concluded that the 3 cases with positive translocation for MAML2 were IMECs, the same conclusion could not be drawn for the 4 cases with negative translocation. Whether the cases that were negative for translocation were GOCs with MEC-like islands or were MAML2-negative IMECs could not be ascertained. Therefore, MAML2 rearrangement is not always reliable in differentiating IMECs from GOCs with overlapping histology.