Primordial odontogenic tumor: a case report and literature review

Abstract

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.

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

“…Microscopically, POTs comprise a myxoid stroma, rich in fusiform and ovoid cells and closely resembling dental papilla, completely surrounded by a single palisaded layer of cuboidal to columnar cells with reverse nuclear polarization. The latter resembles the internal enamel epithelium observed during tooth development [7,8].…”

“…The primordial odontogenic tumor (POT), a newly included entity in the WHO classification, was first described by Mosqueda-Taylor et al [1,2]. It most commonly occurs in the posterior mandible and is associated with unerupted teeth, either in a pericoronal position or surrounding the whole tooth as a "dentigerous cyst-like" radiolucency [7]. The radiographic characteristics in the present case showed radiopaque flecks, whereas POTs are reported as entirely radiolucent lesions [1,2].…”

Primordial odontogenic tumour or developing odontoma?

“…Histologically, the tumour recalls the primary stages of tooth development where neither dentin nor enamel are produced. Their presence, in the case reported by Sun et al ., clearly suggests the possibility of a developing odontoma. Odontoblastic differentiation is evident in the epithelial–mesenchymal interface (as seen in the histopathological image); POT is a benign tumour that originates from early odontogenesis and therefore does not induce odontoblastic differentiation and production of dentin proteins with subsequent presence of dental mineralised tissues Absence of cellularity in the subepithelial region: most of the reported POTs show a remarkable cellularity in the interface between the epithelium surrounding the lesion and the underlying mesenchymal tissue, similar to the papillary condensation that occurs in this area during odontogenesis …”

“…In the second half of this year, Sun et al . reported what they considered to be a new case of POT; however, a critical review of the clinical and histomorphological features of that case led us to consider it to be a developing tooth or perhaps a developing odontoma, rather than a POT.…”

World Health Organization Classification of Odontogenic Tumors and Imaging Approach of Jaw Lesions

“…When the WHO was published in 2017, only seven cases were reported; since then, another four cases were documented in the literature. [16][17][18][19] Young adolescents are most often affected, and the mandible is the site of predilection. Morphologically, the mesenchymal component is variably cellular and loose with stellate fibrous cells.…”