Vascular malformation masquerading as sialolithiasis and parotid obstruction: a case report and review of the literature.

INTRODUCTION Salivary gland obstruction caused by sialolithiasis or duct stricture is one of the more common causes of non-infectious unilateral facial selling. Vascular malformations of the head and neck are less common but may present with intermittent facial swelling. Phleboliths can be found in venous malformations of nearly all adult patients and are a key diagnostic imaging finding. The clinical and radiographic appearance of phleboliths may resemble sialolithiasis, making the diagnosis more difficult. We present a case of intermittent unilateral facial swelling cause by a venous malformation involving the buccal space where the phleboliths were initially misdiagnosed as parotid sialolithiasis. STUDY DESIGN Illustrative case report and literature review. METHODS A 48 year-old woman presented to our office with 9 months of intermittent left facial swelling. On bimanual examination, multiple small firm nodules were palpated in the left cheek. A computed tomography (CT) scan demonstrated multiple oval-shaped radiopaque lesions in the buccal space, initially interpreted as sialoliths. Magnetic resonance imaging (MRI) was obtained, confirming the diagnosis of venous malformation with phleboliths. Sialendoscopy revealed a normal appearing parotid duct system without stricture or sialolithiasis. Ultrasound revealed a buccal space vascular lesion surrounding the distal Stensen's duct. RESULTS Currently, the patient is being observed and is clinically stable. Illustrative CT scan and MRI images are presented. A literature review shows that vascular malformations mimicking salivary gland obstruction are rare. CONCLUSIONS While unilateral facial swelling is commonly due to parotid sialoliths or parotid duct stenosis, other less common causes including vascular malformation should be considered. Phleboliths and sialoliths may appear similar on ono-contrast CT scan. Ultrasound, MRI, and sialendoscopy may be helpful in determining the etiology.