Sclerosing Odontogenic Carcinoma: Report of a Case and Review of the Literature

Sclerosing Odontogenic Carcinoma: A Unique Odontogenic Carcinoma with Metastatic Potential

BACKGROUND

The recent World Health Organization (WHO) classification of odontogenic tumours defines Sclerosing Odontogenic Carcinoma (SOC) as a rare primary intraosseous carcinoma (PIOC) of the jaws. With the exception of one case, there have been no cases of SOC with metastatic disease. We report a unique case of SOC with neck node metastases, further expanding the clinical, radiological and histological spectrum of this rare intriguing tumour.

METHODS

A 52-year-old female presented with a destructive radiolucent lesion of right mandible. Incisional biopsy was interpreted as desmoplastic ameloblastoma. The segmental mandibulectomy specimen was histologically consistent with SOC with positive anterior margin. Further resection with neck dissection revealed positive right levels IB and IIA nodes. Immunohistochemistry and Fluroscent In Situ Hybridization (FISH) were performed to confirm the diagnosis.

RESULTS

The tumour was positive for CK5, p63, p40 and negative for CK19, CK20, CK7, SOX-10, S100, ER, PR, BRAFV600E, and EWSR1 gene rearrangements. Ki67 was 15%.

CONCLUSION

To avoid confusion with PIOC, a high grade squamous cell carcinoma of the jaws with poor prognosis, SOC may be best defined as a rare infiltrative and locally aggressive odontogenic carcinoma with metastatic potential but with a reasonably favourable outcome. SOC shares similar histologic features with many benign and malignant tumours. An appropriate panel of immunohistochemical markers, in conjunction with special stains and molecular studies can help refine the differential diagnosis. It appears that a Ki67 proliferation index of more than 10%, may pose a risk for nodal metastasis and may assist in planning the clinical management. To achieve lower rates of positive margins and tumour recurrence, a wider resection margin (more than a centimetre) is recommended.

Sclerosing Odontogenic Carcinoma With a Prominent Clear Cell Component Mimicking Odontogenic Clear Cell Carcinoma: An Extremely Rare Case With a Fatal Clinical Outcome

Sclerosing odontogenic carcinoma (SOC) is an exceedingly rare odontogenic carcinoma known for its locally aggressive yet indolent behavior. There have been no reports of metastasis to distant organs, except a single case involving lymph node metastasis. This report details the case of a 49-year-old female who presented with a well-demarcated radiolucent lesion in the mandible, accompanied by root resorption and tooth displacement. Microscopically, the lesion exhibited a distinctive composition, with two distinct components: cords of epithelium embedded within an abundant collagenous stroma and solid nests of clear polygonal cells surrounded by hyalinized stroma. Notably, the tumor exhibited direct invasion into the submental muscles, accompanied by perineural and vascular invasion, as well as cortical bone loss. Additionally, the clear cells contained diastase-sensitive periodic acid-Schiff-positive granules. Immunohistochemically, the tumor cells displayed positivity for cytokeratin 19 and p63 while testing negative for myoepithelial markers. The Ki-67 index was measured at 23%. Importantly, neitherEWSR1 nor MAML2 rearrangements were detected through fluorescence in situ hybridization (FISH) analysis. Over several years, this patient experienced three instances of local recurrence; notably, four years after the initial surgery, fludeoxyglucose F18-positron emission tomography (18FDG-PET)/CT scans confirmed the presence of pulmonary metastasis. This case presents an unusual histological variation of SOC, marked by vascular invasion, and is notably the first documented case of a fatal outcome in this context.

Proceedings of the 2023 North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Odontogenic Tumors: Have We Achieved an Evidence-Based Classification

BACKGROUND

The World Health Organization's (WHO) chapter on odontogenic and maxillofacial bone tumors provides a global reference for diagnosis of these tumors. In the fifth edition, the inclusion of consensus definitions and development of essential and desirable diagnostic criteria help improve recognition of distinct entities. These are key enhancements since the diagnosis of odontogenic tumors is largely based on histomorphology which is taken in combination with clinical and radiographic appearances.

METHODS

Review.

RESULTS

Despite delineation of diagnostic criteria for ameloblastoma, adenoid ameloblastoma, and dentinogenic ghost cell tumor, a subset of these tumors continues to show overlapping histological features that can potentially lead to misdiagnosis. Accurate classification may be challenging on small biopsies, but potentially enhanced by refining existing diagnostic criteria and utilization of immunohistochemistry and/or molecular techniques in a specific cases. It has become clear that the clinical and histologic features of the non-calcifying Langerhans cell-rich subtype of calcifying epithelial odontogenic tumor and the amyloid-rich variant of odontogenic fibroma converge into a single tumor description. In addition, this tumor shows remarkable clinical, histological overlap with a subset of sclerosing odontogenic carcinoma located in the maxilla. Benign perineural involvement vs perineural invasion is an underexplored concept in odontogenic neoplasia and warrants clarification to reduce diagnostic confusion with sclerosing odontogenic carcinoma.

CONCLUSION

While controversial issues surrounding classification and discrete tumor entities are addressed in the WHO chapter, ambiguities inevitably remain. This review will examine several groups of odontogenic tumors to highlight persistent knowledge gaps, unmet needs and unresolved controversies.

A case of sclerosing odontogenic carcinoma of the mandible with a review of the literature

Sclerosing odontogenic carcinoma (SOC) is a very rare malignant odontogenic tumor characterized by sclerotic stroma and single-file cord-like tumor cell structures. A 38-year-old man presented with extraoral swelling and right mental region paralysis. Panoramic radiography revealed an ill-defined radiolucent lesion extending from the right mandibular ramus to the right lower canine. Magnetic resonance imaging showed tumor invasion into the right inferior alveolar nerve and masseter muscle. Hemimandibulectomy, bilateral neck dissection, and mandibular reconstruction were performed using a rectus abdominis musculocutaneous flap and a titanium plate. Histopathology and immunohistochemistry confirmed SOC diagnosis. No recurrence occurred in the 1-year follow-up. In this paper, a case of SOC with a high Ki-67 labeling index was reported. Since SOC is prone to nerve invasion, treatment is resection with an appropriate surgical margin.