Peripheral clear cell variant of calcifying epithelial odontogenic tumor affecting 2 sites: report of a case.

A case of clear cell variant of calcifying epithelial odontogenic tumor (CEOT) affecting 2 different extraosseous sites is described. A 43-year-old female patient presented with 2 gingival lesions (1 in the upper premolar and 1 in the lower incisor area), which were clinically diagnosed as inflammatory hyperplasia and surgically removed. Microscopically, both lesions were composed of polyhedral cells (some with clear cytoplasm); hyaline material and areas of calcification were also observed. The diagnostic hypotheses raised were clear cell variant of CEOT, hyalinizing clear cell carcinoma, and renal metastasis. The hyaline material was positive for Congo red, crystal violet, and Lugol's iodine stains, but negative for Coomassie blue; the clear cells showed positively stained granules with PAS stain. Based on these results, the conclusive diagnosis for both lesions was clear cell variant of CEOT. No evidence of recurrence was observed after 1 year of follow-up.