A New Insight into the Classification of Clear Cell Lesions of the Oral Cavity Based on the Diagnostic Modalities Used - A Review.

Clear cell lesions in the oral cavity are relatively uncommon, comprising only 1%-2% of tumors. Histologically, clear cells exhibit distinct cellular characteristics, including a well-defined cell membrane, a nucleus, and a cytoplasm that lacks eosin staining, resulting in a clear appearance. In conjunction with clinical and radiological findings, several commonly used histopathological diagnostic aids are employed, such as hematoxylin and eosin stain, Periodic acid-Schiff stain, mucicarmine stain, and immunohistochemical (IHC) markers. While clear cells can occur in both physiological and pathological conditions, their diagnosis can be challenging, particularly when they comprise the predominant proportion of the tumor mass. The presence of clear cells in tumors often signifies an elevated level of tumor aggressiveness and malignancy. Taking into account the available diagnostic tools and techniques, our objective is to provide a practical framework of classification for approaching clear cell lesions. This classification system will assist clinicians and pathologists in accurately diagnosing and managing such lesions, thereby enhancing their day-to-day clinical decision-making.