AGGRESSIVE CARCINOMA EX-MIXED TUMOR: CASE REPORT

Abstract

Background Salivary malignancies are rare tumors that comprise 5% of head and neck cancers. Salivary tumors are histologically heterogeneous with more than 20 histologic subtypes.1 Some salivary gland tumors, including salivary duct carcinoma and carcinoma ex pleomorphic adenoma (CXPA), are aggressive. CXPA is rare in the minor salivary glands of the oral cavity. We present a case of CXPA arising in the soft palate in a 35-year-old female patient. Clinical and Radiologic Findings The patient presented in 2008 with pain and sensitivity in the left palatine area. On clinical examination, mild intraoral swelling, without exudate, was noted in the left maxillary posterior region. The patient reported that the swelling had been present for almost a year but had recently become enlarged. A panoramic radiograph and a selective periapical radiograph of the maxillary molar region showed the periapical area and sinus boundaries to be within normal limits. A computed tomography (CT) scan taken at that time revealed subtle asymmetric palatal soft tissue fullness indenting/narrowing the lateral pharyngeal airway. The visible lymph nodes on CT were within normal limits according to size criteria. An excisional biopsy was performed, and the palatal mass was diagnosed as carcinoma ex mixed tumor with positive margins, possibly arising from a previously existing pleomorphic adenoma. The patient was referred to a regional medical center for further management of the lesion. The patient revisited the dental school a year later in 2009, with the chief complaint of severe pain and displaced left upper teeth. Patient reported having declined the recommended chemotherapy when initially referred in 2008, and instead, she had consulted with a local doctor and received some herbal injections into the mass. Clinical examination revealed a significantly large lesion protruding into the oral cavity. Cone beam computed tomography (CBCT) revealed an ill-defined expansile, large, radiolucent lesion eroding into the left ethmoidal and maxillary sinus and left nasal cavity and extending up to the floor of the left orbit. CT revealed enlarged lymph nodes. Surgery was declined at that time, and the patient was referred for radiation therapy to shrink the size of the lesion. The cancer metastasized to the liver, lymph nodes, and brain, and the patient died as a result of the disease within a year. Discussion and Conclusions CXPA is an uncommon, high-grade malignant tumor with highly aggressive biologic behavior. Its occurrence in such sites as the soft palate is rare and cause diagnostic difficulties. In this case, a benign pleomorphic adenoma became complicated because of lack of adequate management and the poor choices made by the patient. It underwent high-grade malignant changes and metastasized to various organs of the body, ultimately resulting in the death of the patient.