Purpose: We present a case of a large mucocele pressing the orbit forward and compared our findings with those reported by others.
Case report: A 23-year-old woman was examined for an inflammatory tumor of the internal canthus. She had a 6/10 vision loss of the left eye, diplopia, and non-axial exophthalmos. CT scan and magnetic resonance imaging evidenced a huge sinus mucocele behind the orbit. Surgery using the paralateronasal approach was performed. Pathology confirmed the diagnosis of mucocele.
Discussion: Ophthalmic complications of mucoceles result from tumor growth leading to compressive optic neuropathy or even compression of the chiasma. A sinus mucocele should be suspected upon indirect clinical signs and lead to neuroradiological explorations. Magnetic resonance imaging reveals iso- or high signals on T1-weighted sequences and high signal on T2-weighted sequences. MRI evidences intracranial or orbital extension. CT scan reveal the degree of bone erosion. Prognosis is favorable after surgical treatment. It is important to correctly diagnose mucocele on the basis of clinical and neuroradiological findings in order to propose early surgery and prevent permanent visual loss by compressive optic neuropathy.