Pleomorphic Adenoma
Findings:
A mildly enhancing mass is present in the region of the
right deep lobe of parotid which displaces the parapharyngeal fat medially
and is inseparable from the pterygoid muscles.
Differential Diagnosis:
pleomorphic adenoma, adenopathy, warthins tumor, malignant
salivary gland tumor (adenoid cystic, mucoepidermoid, mixed), lymphoma,
sarcoma
Discussion:
80% of parotid region masses are benign, but there is
considerable overlap between the radiologic appearance of benign and malignant
lesions. Of the benign parotid tumors, 80% are pleomorphic adenomas. Patients
typically present over the age of 50 with a slowly growing mass. In this
case, an important distinction must be made in the space of origin. If
the lesion were originating in the parapharyngeal space, it could be resected
transorally or via the submandibular route. Since this lesion arises from
the deep lobe of parotid, a transparotid approach must be used in order
to gain control of the facial nerve.
reference: Harnsberger, H. R., Handbook of Head and Neck Imaging. 1995:Mosby-Year Book. pp. 35, 69.