Published online Feb 10, 2017. doi: 10.5306/wjco.v8.i1.86
Peer-review started: October 28, 2016
First decision: December 1, 2016
Revised: December 17, 2016
Accepted: January 2, 2017
Article in press: January 3, 2017
Published online: February 10, 2017
Processing time: 103 Days and 16.8 Hours
The intimate anatomical relationship of the facial nerve to the parotid parenchyma has a significant influence on the presenting signs and symptoms, diagnosis and treatment of parotid neoplasms. However, to our knowledge, hyperactivity of this nerve, presenting as facial spasm, has never been described as the presenting sign or symptom of a parotid malignancy. We report a case of carcinoma arising in a recurrent pleomorphic adenoma of the left parotid gland (i.e., carcinoma ex pleomorphic adenoma) that presented with hemifacial spasms. We outline the differential diagnosis of hemifacial spasm as well as a proposed pathophysiology. Facial paralysis, lymph node enlargement, skin involvement, and pain have all been associated with parotid malignancies. To date the development of facial spasm has not been reported with parotid malignancies. The most common etiologies for hemifacial spasm are vascular compression of the ipsilateral facial nerve at the cerebellopontine angle (termed primary or idiopathic) (62%), hereditary (2%), secondary to Bell’s palsy or facial nerve injury (17%), and hemifacial spasm mimickers (psychogenic, tics, dystonia, myoclonus, myokymia, myorthythmia, and hemimasticatory spasm) (17%). Hemifacial spasm has not been reported in association with a malignant parotid tumor but must be considered in the differential diagnosis of this presenting symptom.
Core tip: This report represents the first case of hemifacial spasm associated with transformation of a recurrent pleomorphic adenoma into a carcinoma ex pleomorphic adenoma. The causation of hemifacial spasms is discussed.