The Challenging Diagnosis of Primordial Odontogenic Tumor

Histopathological spectrum of primordial odontogenic tumor with co-existing dentigerous cyst: 1st reported case of the world with a proposed 'updated diagnostic criteria'

BACKGROUND

POT is a relatively newly described benign odontogenic tumor with very few cases registered to date. We present the 1st case of Primordial odontogenic tumor (POT) from Sub-Saharan Africa with unique clinicopathological features; also, this is the first case to report POT's existence as a Hybrid Odontogenic lesion (HOL), with a pertinent review of the literature.

CASE PRESENTATION

This was a 17-year-old patient who presented with slow-growing, painless posterior mandibular swelling. The imaging revealed a well-defined, unilocular, expansile, lytic lesion with internal calcific foci surrounding an impacted #36, indicating a calcifying odontogenic cyst. The incisional biopsy revealed the presence of POT. The tumor was excised along with the involved tooth.

CONCLUSION

POT is predominantly a non-aggressive and mostly affects the pediatric population. Hence, clinicians must be updated on all the aspects of this tumor to diagnose it appropriately and avoid any undue over-or under-treatment.

Primordial Odontogenic Tumor: A Decade Post-Description Systematic Review

BACKGROUND

Primordial odontogenic tumor (POT) is a rare benign tumor arising from odontogenic epithelium and ectomesenchyme. It typically presents in children and young adults. POT is often found in the posterior mandible and frequently presents as asymptomatic swelling. A systematic review of the literature was conducted to comprehensively analyze the clinicopathologic features of this rare entity over the past ten years.

METHODS

A systematic review of POT case series and case reports following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines was performed. Data on demographics and clinical characteristics, including age, sex, clinical presentation, duration of the lesion, location, and radiographic and histological features, were extracted. A quantitative description of immunohistochemical studies reported in the literature was also performed. Treatment, a follow-up period, and recurrence were collected for analysis.

RESULTS

This review included 26 studies involving 36 POT cases. Patients often presented with asymptomatic swelling at a median age of 12 years, with a male-to-female ratio of 1.18:1. The posterior mandible was the most commonly affected site, while three cases were noted in the anterior region exclusively in the maxilla. Most lesions appeared as unilocular radiolucencies with well-defined borders; however, five cases exhibited fine trabeculation or radiopacities. The primary histological features observed in POT included ectomesenchymal stroma lined by columnar cells with nuclear reverse polarity. Most cases were treated through enucleation and curettage (50.0%), followed by tumor excision (36.1%). Only one case demonstrated recurrence among the 29 cases with known follow-up information.

CONCLUSION

This study offers comprehensive and current descriptive data on POT, enhancing the ability of clinicians and pathologists to accurately identify these rare lesions and thereby avoid misdiagnosis and inappropriate management.

Primordial Odontogenic Tumor; Archival Review of 19380 Cases in a 55-Year Retrospective Study

BACKGROUND AND OBJECTIVE

Primordial odontogenic tumor is a rare odontogenic tumor reported for the first time in 2014. It was included in the latest edition of World Health Organization classification of Head and Neck Tumors as a new benign mixed epithelial-mesenchymal neoplasm. To date, 26 cases has been reported in literature. The aim of this study was to determine the possible presence of primordial odontogenic tumor in the previously diagnosed cases with myxoid stroma.

MATERIALS AND METHODS

This study was a retrospective descriptive study that was concluded in Oral and Maxillofacial Pathology Department, School of Dentistry, Tehran University of Medical Sciences. We reviewed all 19,380 cases from 19,66 to find the lesions with myxoid stroma which were in differential diagnosis with primordial odontogenic tumor. These cases should be associated with an impacted or unerupted tooth and belong to the patients under 20 years old.

RESULTS

We find 503 pericoronal lesions with myxoid stroma. Three cases were isolated after recut and reevaluation for finding fulfill histologic features. After immunohistochemical analysis, we find a new case of developing primordial odontogenic tumor associated with odontoma.

DISCUSSION

Primordial odontogenic tumor a recently described odontogenic tumor has a well-defined clinicopathological and immunohistochemical profile and should be differentiated from the others pericoronal lesions. It is the first time that this archival review has been done to find probable cases of primordial odontogenic tumor.

Recurrent Primordial Odontogenic Tumor: Epithelium-Rich Variant

Primordial odontogenic tumor (POT) is a rare, mixed odontogenic neoplasm composed of spindled and stellate-shaped cells in myxoid stroma resembling dental papilla, surfaced by cuboidal-to-columnar odontogenic epithelium. Most POTs present in the posterior mandible as a well-demarcated radiolucency associated with a developing tooth in children and adolescents. POT is treated conservatively with no recurrences documented to-date. To describe the clinicopathological features of a recurrent POT. A 19-year-old female presented with an asymptomatic swelling, and panoramic radiograph revealed a multiloculated radiolucency in the mandibular body and ramus, with buccal and lingual perforation. The tumor was composed of plump spindle and stellate cells in a delicately collagenous and myxoid stroma, surfaced by columnar epithelial cells with reverse nuclear polarization. There was extensive epithelial proliferation forming invaginations within the tumor mass and organoid/enamel organ-like structures with enameloid-like deposits, dentinoid, and dystrophic calcifications. This was similar to the POT that had been excised four years prior from the same location. The patient underwent hemi-mandibulectomy and currently is free of disease at a thirteen-month follow-up. This report describes the first recurrent POT exhibiting extensive epithelial proliferation.

A Case Report of Primordial Odontogenic Tumor That Required Distinction from a Dentigerous Cyst

Primordial odontogenic tumor (POT) is a rare odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla and covered by cuboidal to columnar epithelium. We herein report a case of POT in a 14-year-old boy. Computed tomography (CT) exhibited a round cavity with a defined cortical border circumscribing the tooth of the second molar. However, the gross finding was a solid mass, not a cyst. Histologically, the tumor consisted of dental papillalike myxoid connective tissue covered by columnar epithelium. Therefore, although the clinical diagnosis was dentigerous cyst (DC), we diagnosed POT based on histologic findings. Clinical findings of POT resemble DC, but the clinical behavior of POT is different to DC, such as cortical expansion and root resorption of teeth. Therefore, histological differentiation of POT from DC is critical for accurate diagnosis.

Primordial odontogenic tumor: A systematic review

Background

The primordial odontogenic tumor (POT) is a recently described benign entity with histopathological and immunohistochemical features suggesting its origin during early odontogenesis. Aim: To integrate the available data published on POT into a comprehensive analysis to better define its clinicopathological and molecular features.

Material and Methods

An electronic systematic review was performed up to September 2019 in multiple databases.

Results

A total of 13 publications were included, representing 16 reported cases and 3 molecular studies. The mean age of the affected patients was 11.6 years (range 2-19), with a slight predominance in males (56.25%). The posterior mandible was the main location (87.5%), with only two cases affecting the posterior maxilla. All cases appeared as a radiolucent lesion in close relationship to an unerupted tooth. Recurrences have not been reported to date. Microscopically, POT comprises fibromyxoid tissue with variable cellularity surrounded by a cuboidal to columnar odontogenic epithelium but without unequivocal dental hard tissue formation. A delicate fibrous capsule surrounds (at least partially) the tumor. The epithelial component shows immunohistochemical positivity for amelogenin, CK19, and CK14, and variable expression of Glut-1, Galectin-3 and Caveolin-1, Vimentin, p-53, PITX2, Bcl-2, Bax and Survivin; the mesenchymal tissue is positive for Vimentin, CD90, p-53, PITX2, Bcl-2, Bax, and Survivin, and the subepithelial region exhibits the strong expression of Syndecan-1 and CD34. The Ki-67 index is low (<5%). The negative or weak expression of dentinogenesis-associated genes could explain the inhibition of dentin and subsequent enamel formation in this neoplasm.

Conclusions

POT is an entity with a well-defined clinicopathological, immunohistochemical and molecular profile that must be properly diagnosed and differentiated from other odontogenic lesions and treated consequently.

Key words:Primordial odontogenic tumor, systematic review.

Dental Germ Tumor: An Unusual, Cystic, Mixed Epithelial-Mesenchymal Odontogenic Tumor

Although odontogenic lesions have been extensively described and studied, anomalous, challenging cases occasionally come to the attention of the pathologist. Here, we report the clinical and microscopic characteristics of an unusual cystic lesion of odontogenic origin. A 16-year-old male presented with swelling and pain to palpation of the right mandible as well as numbness of the right lower lip. Radiographically, the corresponding lesion was well-defined and radiolucent with internal radiopaque foci. It extended from the right first premolar posteriorly, approaching the angle of the mandible, and involved the mandibular first molar which was impacted and displaced. The second and third right mandibular molars were also impacted and displaced. The patient was treated by excisional biopsy under general anesthesia. The histopathologic examination revealed the presence of multicystic areas lined by a thin, non-keratinizing squamous epithelium that resembled the epithelial lining of a dentigerous cyst. In continuity with the cystic lining, areas of myxoid tissue reminiscent of dental papilla were observed. The myxoid tissue formed structures that were surfaced by an epithelium comprising a basal layer of ameloblast-like cells with reverse polarity of the nuclei. Above the basilar cells, additional layers of epithelial cells composed a structure resembling the enamel organ. Subjacent to the basilar ameloblast-like cells, a condensation of mesenchymal cells with polarized nuclei opposite to the ameloblast-like cells was present. These mesenchymal cells resembled odontoblasts. In addition, numerous mineralized structures amongst the odontogenic epithelial tissue were present. To date, the patient remains well and without evidence of recurrence after 36 months of follow-up.

Primordial odontogenic tumor: a case report and literature review

Background

A primordial odontogenic tumor (POT) is a rare, benign, mixed epithelial and mesenchymal odontogenic tumor that has been included as a new entity in the latest World Health Organization (WHO) classification (2017). POT consists of dental papilla-like myxoid connective tissue covered with a delicate membrane of ameloblastic epithelium. Only 15 cases have been documented worldwide, and here, we report the sixteenth case and the first one of South Korea.

Case presentation

An asymptomatic lesion was discovered as an incidental radiographic finding in a 10-year-old boy. The patient had no complaints about the lesion. Cone-beam computerized tomograms revealed a round cavity with a defined cortical border measuring approximately 5 × 5 × 5 mm in size. The lesion was a POT. The patient was treated with enucleation. The tumor showed no recurrence for one year.

Conclusion

This is the first report of POT in South Korea using the novel diagnosis of POT after it was recognized and defined in the latest WHO classification. This novel diagnosis will be useful for pathologists and clinicians in diagnosing and differentiating this new and rare disease from other odontogenic tumors.