F-18 FDG PET/CT Findings of dedifferentiated acinic cell carcinoma

Dedifferentiated acinic cell carcinoma is a rare variant of acinic cell carcinoma with a poorly differentiated component. Although acinic cell carcinoma is a relatively low grade form of malignant salivary gland tumor, the dedifferentiated variant demonstrates very aggressive behavior. The authors present a case of a 52-year-old man presenting with a palpable infra-auricular mass. F-18 fluorodeoxy glucose positron-emission tomography/computed tomography was performed for initial staging work-up, and intense fluorodeoxy glucose uptake was noted in the parotid gland mass. Dedifferentiated acinic cell carcinoma arising in the parotid gland was confirmed by surgery.