The preoperative diagnosis of a paranasal epidermoid cysts (EC) is challenging and is frequently mistaken. We present the case of a patient who developed a swelling on the left side of the face. The clinical examination showed a fixed and poorly defined swelling in the left maxillary region, with a slightly painful bulge in the upper vestibular peri-gingival area. A computed tomography (CT) scan showed a well-encapsulated expansive hypodensity that filled the left maxillary sinus. Magnetic resonance imaging (MRI) revealed a mass hypo-intense on T1-weighted images, high intense on T2-weighted images, hyperintense on diffusion-weighted images, and had a low apparent diffusion coefficient with no contrast uptake observed after the injection of Gadolinium. Surgical excision under general anesthesia was considered. A combined approach using an endoscopic sinus and Caldwell-Luc approach was performed and the histopathological examination confirmed the diagnosis of an EC. In conclusion, the preoperative imaging, including CT scans and MRI, aids in diagnosing ECs and differentiating them from other sinus tumors. Postoperative follow-up involving endoscopic surveillance and CT scans is crucial to monitor for potential recurrence.
Keywords: computed tomography; diffusion weighted imaging; magnetic resonance imaging; sinus epidermoid.