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Updated: Mar 1, 2026

Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas
Published on: February 28, 2019
A case of primordial odontogenic tumor: A new entity in the latest WHO classification (2017)
Toshinori Ando1, Madhu Shrestha1, Takashi Nakamoto2
1Department of Oral and Maxillofacial Pathobiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Abstract:
Primordial odontogenic tumor (POT) is a rare lesion in the jaw which has been included as a new entity of benign mixed epithelial and mesenchymal odontogenic tumour in the latest World Health Organization (WHO) classification (2017). Only seven cases have been reported. It typically occurs in the posterior mandible. We report an additional case of POT in the maxilla of an 8-year-old girl presenting with an asymptomatic buccal enlargement. A well-defined, unilocular, radiolucent lesion was observed radiographically. Histologically, the tumor was mostly composed of loose fibrous connective tissue resembling dental papilla and a single layer of columnar epithelium covering the periphery of the tumor. In part, cords or nests of epithelium were present in the mesenchyme close to the periphery. Nestin, a marker of odontogenic ectomesenchyme, was positive in the mesenchymal tumor cells. We finally diagnosed the lesion as POT considering the possibility of other odontogenic tumors like ameloblastic fibroma or developing odontoma as a differential diagnosis. The patient shows no recurrence after 16 months. This case is the first report from Japan using this novel diagnosis POT after it was recognized and defined in the latest WHO classification.
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