Abstract: Objective To study the clinical characteristics, diagnosis and treatment of the malignant parapharyngeal space tumors. Methods A retrospective study of 5 patients with primary malignant parapharyngeal space tumors treated from 2000 to 2013 was performed. All the 5 patients received B-ultrasound and CT scan, while 3 patients underwent further enhanced MRI scanning. The transcervical approach surgery was applied in 5 patients and functional neck dissection was performed in 2 patients. Postoperative radiotherapy were applied in 3 patients. Final diagnosis was reached by frozen section and pathological studies. Results There were one malignant neurofibroma, one malignant peripheral nerve sheath tumor, one branchial cleft carcinoma, one synovial sarcoma, and one undifferentiated carcinoma. Preoperative imaging studies were very important for precise tumor localization and its relation to adjacent structures. 3 patients were alive in 1-year following-up, however, 1 patient died 3 years later and 1 patients was gone half a year later after the operation. Conclusion The malignant parapharyngeal space tumors are various in histopathology. B-ultrasound, CT scan and enhanced MRI study are helpful for diagnosis. Appropriate approach is key in the surgery of parapharyngeal space tumors. Comprehensive treatment is very important to the prognosis.

Key words: Malignant tumor, Surgery, Diagnosis, Parapharyngeal space