Pneumosinus Dilatans Case Mimicking OrbitalPathology In Patient With Visual Loss

Pneumosinus dilatans is an abnormal localized dilatation of paranasal sinuses. Although cranial magnetic resonance imaging can help for differentiation of paranasal sinuses, variations maybe misdiagnosed as a lesion. Susceptibility artifacts may be formed around tissues where the magnetic field sensitivity differs and these can be easily recognized. Atypical appearance atthese susceptibility artifacts can cause pseudolesion appearances that in turn cause misdiagnoses.If the artifact do not differentiation from the lesion, computed tomography should be performed.For this reason, in the differential diagnosis of lesions especially close to the paranasal sinuses, benign formations like sinus variations should be kept in mind in the cranial and orbital MRI.In this case, we aimed to present a case diagnosed at pneumosinus dilatans in control cranial computed tomography evaluation who came with loss of vision and is found pseudolesion appearance in orbital region neighbourhood in MRI.