Primary intraosseous adenoid cystic carcinoma of the mandible: histopathological and immunohistochemical analysis.

Primary intraosseous salivary gland tumors of the mandible are rare, with mucopidermoid carcinoma being the most frequent, followed by adenoid cystic carcinoma (ACC). We present a case of a central ACC involving the mandible of a 46-year-old man. He presented an indurated swelling on the vestibular aspect of the left mandibular body and ipsilateral paraesthesia of the lower lip. A panoramic radiography revealed a large radiolucent area, with irregular margins, involving the body and ramus of the left mandible, and CT scan confirmed that the lesion was confined within the mandibular bone. The histopathological features were of an ACC. CT scan also revealed multiple nodular lesions in both lungs suggestive of metastases. The patient was surgically treated by hemi-mandibulectomy. The patient is well with no evidences of recurrences in the mandible. The present case shows that the clinical and immunohistochemical profile of primary intraosseous ACC is similar to what is found in ACC involving the salivary glands.