Clear cell variant of calcifying epithelial odontogenic tumor (CEOT) in the maxilla: report of a case with immunohistochemical and ultrastructural investigations

A rare case of clear cell variant of calcifying epithelial odontogenic tumo r is presented with immunohistochemical and ultrastructural investigations. A 14-year-old Japanese girl was admitted with a complaint of swelling in t he right posterior maxiila. Radiological examination showed a well-circumsc ribed radiolucent lesion located close to the impacted third molar. After o nly a partial tumor excision, the tumor recurred 13 years later. It appeare d radiologically as an irregular radio-density, and a subtotal maxillectomy was performed. Histological examination showed sheets and/or strands compo sed almost entirely of clear vacuolated epithelial cells in a stroma contai ning intercellular amyloid-like material and calcification. Histochemical a nd ultrastructural analysis detected cytoplasmic glycogen granules in the c lear cells, and positive immunoreactivities for cytokeratins 8, 13 and 19; filaggrin and anti-ameloblastoma antibodies suggested an odontogenic epithe lial origin.