A more appropriate clinical classification of benign parotid tumors: investigation of 425 cases.

CONCLUSIONS It is appropriate to clinically classify benign parotid tumors into three groups, i.e. superficial tumors, deep tumors, and lower pole tumors. OBJECTIVE It is important to classify benign parotid tumors based on location when deciding the surgical strategy and conducting clinical research. In this study, we examined a classification of benign parotid tumors that was useful for clinical practice. METHODS We studied 425 patients with benign parotid tumors who underwent surgery at our hospital. Their age, gender, tumor histopathology, maximum tumor diameter, postoperative facial nerve paresis, operating time, and blood loss were investigated after classifying the tumors as superficial tumors, deep tumors, or lower pole tumors. We also investigated the same parameters after dividing the lower pole tumors into superficial and deep types. RESULTS Lower pole tumors had distinct characteristics from superficial and deep tumors. The incidence of facial nerve paresis was significantly higher and the operating time was significantly longer for deep tumors than for either superficial or lower pole tumors, while there were no significant differences between superficial and lower pole tumors. In addition, there were no significant differences in any of the parameters between the superficial and deep types of lower pole tumor.