Clear and Spindle Cell Dedifferentiation in Ameloblastic Carcinoma: A Case Report on a Uncommon Phenomenon

Indian J Otolaryngol Head Neck Surg. 2024 Feb;76(1):1229-1233. doi: 10.1007/s12070-023-04232-z. Epub 2023 Oct 1.

Abstract

Ameloblastic carcinoma is a rare malignant neoplasm with characteristic histopathological features that are directed towards an aggressive surgical approach than benign odontogenic lesions. It affects people of all ages, mostly in the posterior mandible, without a preference for race or gender. De novo cancer is one of its primary types, while the second type is defined as a malignant change from an antecedent case of benign ameloblastoma. The rapid progression of molecular biology led to the revelation that ameloblastoma contains a BRAF-V600E genetic mutation over 60%. Besides conventional ameloblastic carcinomas, rare histologic variants have also been described in the literature, including clear and spindle cells. These variants pose diagnostic challenges as to whether it is a dedifferentiation or a distinct entity. The dearth of data lends credence to the notion that these histologic variations are related to high-grade neoplasms and more aggressive outcomes. As a result, the current report intends to analyze a series of patients diagnosed with conventional ameloblastic carcinoma of the head and neck region with spindle and clear cell types along with a brief assessment of the literature.

Keywords: Ameloblastic carcinoma; Beta-catenin; Clear cell; Cytokeratin; Spindle cell.