Clear Cell Odontogenic Carcinoma of the Mandible Harboring EWSR1 Rearrangement: Report of a Massive Jaw Tumor and Review of Diagnostic Considerations

Figure 2

Histopathology of clear cell odontogenic carcinoma of the mandible in a 43-year-old female patient. (a) Morphology shows nests and cords of round to polygonal monomorphic clear epithelial cells with prominent stromal hyalinization containing lymphocytes (H&E 100x). (b) Higher magnification (H&E 400x). (c) Clear epithelial cells positive for PAS demonstrating intracytoplasmic granules (PAS 200x). (d) Clear epithelial cells are negative after PAS-D (200x). (e) Split of the green signal from the red signal by break-apart FISH demonstrates that the tumor harbors EWSR1 rearrangement. In contrast, the uninvolved EWSR1 allele shows a yellow signal (resulting from the fused red and green probes).

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