Frontoethmoidal Mucocele

Maria V. Suurna and Lee A. Zimmer

History

A 78-year-old man complains of diplopia, frequent headaches, and swelling of the right eye for 3 months. The patient underwent functional endoscopic sinus surgery for chronic sinusitis several years ago.

The head and neck examination notes swelling over the right side of the forehead and right upper eyelid. The right eye has mild proptosis, inferior-lateral displacement, and decreased extraocular mobility. Nasal endoscopy reveals bilateral scarring of the middle meatus.

Differential Diagnosis—Key Points

1. Mucocele is a chronic cystic mucus-filled lesion of the paranasal sinuses secondary to obstruction of sinus outflow tracts. The outflow obstruction leads to the development of mucoceles. This may be a result of trauma, chronic sinusitis, sinonasal polyposis, neoplasms, or sinus surgery. Mucoceles may expand over a period of many years before becoming symptomatic. The mucocele may become infected, forming a mucopyocele. Frontoethmoidal mucocele is the most common paranasal sinus mucocele. Patients often present with frontal headache, proptosis, and diplopia secondary to downward and outward displacement of the globe.

2. Osteoma is the most common tumor of the paranasal sinuses and is commonly found in the frontoethmoidal region. Presenting symptoms are related to slow expansion of the lesion leading to impingement and displacement of normal structures. Other fibro-osseous and bony lesions such as fibrous dysplasia and ossifying fibroma should also be considered in the differential diagnosis.

3. Inverted papilloma is a benign tumor of the paranasal sinuses characterized by inverted growth pattern. There is about a 10% risk of associated squamous cell carcinoma.

4. Other benign neoplasms include meningiomas, schwannomas, neurofibromas, hamartomas, hemangiomas, and chordomas.

5. The Pott puffy tumor is a subperiosteal abscess of the frontal bone associated with frontal osteomyelitis. It can result from acute and chronic frontal sinusitis and often manifests with localized swelling overlying the forehead.

6.