Salivary duct carcinoma ex pleomorphic adenoma of the palate: a case report.

Carcinoma ex pleomorphic adenoma is a rare malignancy of the head and neck, particularly in the minor salivary glands. Most cases arise in the major salivary glands, most commonly in the parotid gland, followed by the submandibular gland. The malignant component of the tumor varies, but can be salivary duct carcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma, squamous cell carcinoma, or adenocarcinoma, not otherwise specified. Primary salivary duct carcinoma is also a rare malignancy of the head and neck. Similar to carcinoma ex pleomorphic adenoma, it is more common in the major salivary glands, with the parotid gland accounting for 88% and the submandibular gland for 10% of cases. To date, only 25 known cases of primary salivary duct carcinoma arising in the minor salivary glands have been documented, with most arising in the palate. Salivary duct carcinoma ex pleomorphic adenoma of the minor salivary glands appears to be even rarer. Our case of salivary duct carcinoma ex pleomorphic adenoma of the palate is the first complete report, to our knowledge, in the English-language scientific literature.