Necrotizing sialometaplasia of the parotid gland associated with facial nerve paralysis.

INTRODUCTION: Necrotizing sialometaplasia is a benign inflammatory lesion involving most frequently the minor salivary gland of the hard palate. Involvement of the parotid gland is rare, involvement of the parotid gland associated with facial palsy is exceptional. CASE REPORT: A 56-year-old male patient with Marfan syndrome presented with swelling and inflammation of the left parotid gland associated with progressively complete facial nerve paralysis. CT scan and MRI showed a parotid collection with hyper signal of the nearest tissues associated with erosion of the styloid process. A malignant tumor was suspected. The histological examination of a biopsy showed a lobulocentric process with necrosis, squamous metaplasia, and inflammation. The immunohistochemical examination supported a final diagnosis of necrotizing sialometaplasia. DISCUSSION: Necrotizing sialometaplasia of the parotid gland associated with facial nerve paralysis presents like a malignant neoplasm, both clinically and histologically. Only advanced immunohistochemical examination can really confirm the diagnosis.