Amyloidoma Involving the Orbit, Meckel's Cave and Infratemporal Fossa: 3T MRI Findings.

Amyloidoma is a rare lesion characterized by tissue deposition of an abnormal fibrillary protein (amyloid). It is the focal and localized counterpart of systemic amyloidosis, where the deposition of amyloid diffusely involves several organs. The few literature reports of intracranial amyloidomas include lesions involving the pituitary gland, orbit, cerebral hemispheres, temporal bone, cerebellopontine angle and jugular foramen. We describe the case of a 27-year-old woman presenting with painless slowly progressive proptosis of the right eye. The patient underwent a contrast-enhanced CT study of the head, followed by 3T MRI which disclosed a homogeneous mass in the right Meckel's cave and cavernous sinus, extending through an enlarged foramen ovale to the infratemporal fossa. The right optic nerve and ocular muscles were enlarged and infiltrated along with the retrobulbar fat by contrast-enhancing tissue. Thin contrast-enhanced MRI scans through the area of interest showed the mass to extend posterior to t...