Adenocarcinoma of the parotid gland with calcification

A 78-year-old Korean woman was referred to Chonbuk National University Dental Hospital complaining of facial palsy and palpable mass in the right parotid gland area for 4 years. Clinical examination showed an asymmetrical facial appearance due to a 4 cmx5 cm hard, fixed, non-tender mass in the right parotid gland area, incomplete eye closure and a slight tremor at the corner of the mouth. A panoramic radiograph showed an amorphous calcified mass on the posterior mandibular ramus with thinning of the cortical plate adjacent to the mass. A sialogram showed constriction of the main duct and no further filling of striated, intercalated ducts and parenchymal areas. CT indicated an expansile mass with slight contrast enhancement involving the right parotid gland. The large mass showed necrotic areas and calcifications. A bone scan showed marked accumulation of (99)Tc(m)-methylene diphosphonate on the right posterior maxilla. Microscopic findings revealed minimal morphological alterations and rare mitotic figures within tumour cells, and the lesion was diagnosed as adenocarcinoma not otherwise specified (NOS, grade II).