BACKGROUND: Sclerosing odontogenic carcinoma is a rare primary intraosseous neoplasm that was featured recently as a single entity in the World Health Organization classification of Head and Neck Tumors 2017, with only 14 cases published to date. The biological characteristics of sclerosing odontogenic carcinoma remain indistinct because of its rarity; however, it appears to be locally aggressive, with no regional or distant metastasis reported to date.
METHODS: We reported a case of sclerosing odontogenic carcinoma of the maxilla in a 62-year-old woman, who presented with an indolent right palatal swelling, which progressively increased in size over 7 years. Right subtotal maxillectomy with surgical margins of approximately 1.5 cm was performed. The patient remained disease free for 4 years following the ablation surgery. Diagnostic workups, treatment, and therapeutic outcomes were discussed.
CONCLUSIONS: More cases are needed to further characterize this entity, understand its biological behavior, and justify the treatment protocols. Resection with wide margins of approximately 1.0 to 1.5 cm is proposed, while neck dissection, post-operative radiotherapy, or chemotherapy are deemed unnecessary.

Both clear cell odontogenic carcinoma (CCOC) and sclerosing odontogenic carcinoma (SOC) are rare odontogenic malignancies. Here, we report a case of maxillary CCOC whose clinical and histologic features resembled those of SOC. Radiologically, the tumor presented as an ill-defined, expansile radiolucency with local bone destruction. Histologically, the tumor was comprised of thin cords or strands of odontogenic epithelium permeating through a sclerosed fibrous stroma with occasional clear cell foci. It damaged the cortical plates and invaded the adjacent soft tissue. Immunohistochemical expression of Pancytokeratin, Cytokeratin 19, p63, Cytokeratin 5/6, and Cytokeratin 14, as well as focal expression of Cytokeratin 7, demonstrated the epithelial nature of the tumor. Alcian Blue Periodic acid Schiff staining revealed a lack of intracellular mucin. Fluorescence in situ hybridization analysis revealed Ewing sarcoma RNA binding protein 1 and activating transcription factor 1 gene translocation, further confirming the diagnosis of CCOC. Lastly, we contextualized the genetic analysis of our case to that of CCOC in the literature.

Sclerosing odontogenic carcinoma (SOC) is a primary intraosseous carcinoma of the jaw that was listed as a separate entity for the first time in the latest version of the World Health Organization classification of Head and Neck Tumors (2017). In this report, we present a case of SOC involving a circuitous diagnostic process because of the inadequately detailed biopsy findings and inherent impression based on the imaging manifestations. Through an extensive literature review, the histopathological and immunohistochemical features of the disease were briefly summarized. Radiological findings of SOC have been characterized in detail, and an imaging classification scheme has been proposed to further discuss the diversity of radiographic features. Due to the rarity of the disease, a comprehensive understanding of SOC is needed, and close collaboration between clinicians, radiologists, and pathologists is crucial to avoid misdiagnosis.