Lack of enrollment of eligible patients for randomization.

The most common benign tumor of the parotid gland is the so called pleomorphic adenoma. Although benign, this tumor may recur after surgical removal due to tumor cells left behind during the surgical operation. Thus, pleomorphic adenomas have been treated with wide resection similar to malignant tumors. This extensive surgery often leads to injury to the motor nerves responsible for facial expression and eye protection. The investigators propose less extensive surgery which should be thorough enough to prevent tumor recurrence while keeping the facial nerve out of risk.

Pleomorphic adenoma is notorious of its propensity to local recurrence due to the microscopic extracapsular extension of the tumor. Superficial parotidectomy (SP) is the standard treatment. Extracapsular dissection (ED) has been proposed to minimize the risk of facial nerve palsy. However, the oncologic safety of ED is controversial in the literature. We propose quadrant parotidectomy (QP) which is less radical than SP and less conservative than ED. QP entails dissection overlying one primary division of the facial nerve leaving the other division undisturbed while the resection safety margin is still generous.

Surgery for pleomorphic adenoma is a compromise between radicality and facial nerve morbidity. Risk of local recurrence is imprecisely described in the literature and is universally regarded as infrequent and remote. Many studies did not report recurrent cases. Thus, Facial nerve injury is the main concern of parotid surgeons and is considered the primary end point of this study.

Inclusion Criteria:

• Adult patients with pleomorphic adenoma of the parotid gland with Cytology- proven diagnosis

Exclusion Criteria:

• Collagen diseases
• Previous parotid surgery
• Previous facial nerve palsy
• Neuromuscular diseases affecting the face
• Patient refusal