True about parotid tumor is all except

Eight percent salivary neoplasms are in the parotids of which 80% are benign ; 80% of these are pleomorphic adenomas. Parotid tumours are common but only 20% are malignant.Facial nerve involvement -lower facial nerve palsy-(difficulty in closing eyelid,difficulty in blowing and clenching teeth) indicates malignancy.Superficial parotidectomy is done if only superficial lobe is involved. And 80% of tumours occur in superficial lobe. SRB,5th,414.