Acinic cell tumour of the maxillary sinus: an unusual case initially diagnosed as parotid cancer.

An unusual case of acinic cell tumour of the maxillary sinus is presented. The patient, a 41-year-old male who had undergone incomplete excision of the tumour in the left parotid region previously, was referred to our department for further treatment. The initial pathological diagnosis was adenocarcinoma of the parotid gland. CT-scan not only revealed tumours in the left pre-auricular and upper neck region, but also an enhanced mass in the left maxillary sinus. Although there were neither nasal symptoms nor destruction of the maxillary bone, aspiration biopsy of the maxillary sinus revealed class V. Total maxillectomy, radiotherapy and systemic chemotherapy were performed just after total parotidectomy and radical neck dissection at the left side. The clinical and histopathological findings are discussed.