Sclerosing odontogenic carcinoma presenting on the hard palate of a 43-year-old female: a case report.

We present a case of sclerosing odontogenic carcinoma (SOC) occurring on the hard palate of a 43-year-old female. The tumor presented as an asymptomatic firm swelling and histopathologically was characterized by widely dispersed nests and cords of bland cells infiltrating between hyalinized collagen fibers. Prominent perineural and intraneural invasion and erosion of bone was noted. The tumor cells showed staining with antibodies to pan-cytokeratin (PanCK), cytokeratin 19 (CK19), cytokeratin 5/6 (CK5/6), cytokeratin 14 (CK14), p63 and E-cadherin, but no staining with antibodies to carcinoembryonic antigen (CEA), cytokeratin 7 (CK7), cytokeratin 20 (CK20), estrogen receptor (ER), progesterone receptor (PR) or S100. Staining for mucin with alcian blue/periodic acid-Schiff with diastase was equivocal, with no definite evidence of mucin or muciphages. An initial diagnosis of adenocarcinoma NOS was made upon incisional biopsy, with the prominent filing pattern and cytoplasmic vacuolization prompting consideration of metastatic breast cancer in the first instance. The true nature of the tumor became clear after staging investigations and surgical resection. The patient was treated by surgery alone and is disease-free after 17 months.