Post-Traumatic Mucoceles: Does Encephalomalacia Predict Advanced Disease?

Introduction: Mucoceles are a rare delayed complication of frontal sinus fractures. Although usually heralded by typical sinonasal symptoms, advanced disease can present with meningitis or facial disfigurement (forehead swelling, globe dystopia) due to posterior or anterior table erosion, respectively. The forceful anterior impact required for frontal sinus fractures is also capable of contusing the frontal lobes, which may impair executive function. Such a cognitive deficit may permit the development of advanced disease despite asymptomatic facial disfigurement. Because encephalomalacia precedes mucocele formation, patients with frontal lobe injury may warrant closer radiographic surveillance.

Study Design: A retrospective chart review and analysis were performed.

Methods: Following IRB approval, the electronic medical record was queried for patients with a history of facial trauma and sinonasal mucocele presenting over the past 15 years. Charts were reviewed for mechanism and date of injury, presenting symptomatology, radiographic features (encephalomalacia and the number of spaces involved by mucocele), and surgical management. Patients with trauma that spared the sinonasal mucosa were excluded.

Results: Thirteen patients met study criteria and were included in analysis (1 woman; average presenting age 45 years). The mean duration between injury and presentation was 20.8 years (range, 9.4–37.2 years). Five patients had undergone frontal sinus surgical management (e.g., obliteration, cranialization) before presentation. Seven patients had radiographically apparent encephalomalacia. Such patients were more likely to present with facial disfigurement (85.7% vs. 16.7%, P = 0.009); there was also a trend toward more extensive disease (4.1 vs. 2.3 involved spaces) and a longer duration of presenting symptomatology (10 vs. 1.5 months) among patients with encephalomalacia. Eight patients were managed by a primarily endonasal endoscopic approach, three of whom had adjunctive frontal trephination. A primarily open approach was employed in four patients, two of whom were endoscope-assisted. At the time of review, one patient has not undergone surgery.

Conclusions: The delay between injury and declaration of post-traumatic mucoceles can be decades long. Patients with associated encephalomalacia seem to observe worrisome symptoms and present with advanced disease. Although all patients at risk for mucocele should undergo prolonged radiographic follow-up, close attention should be given to those patients with frontal encephalomalacia.