Primary localized amyloidosis presenting as diffuse amorphous calcified mass in both orbits: case report.

Primary localized amyloidosis is rare in the orbit. We report the case of a 63-year-old woman that presented with bilateral proptosis and ophthalmoplegia. A computed tomography scan revealed an infiltrative amorphous and markedly calcified mass in both orbits while a magnetic resonance scan showed a heterogeneous hypointense signal on T2-weighted images. A biopsy was performed through an anterior orbitotomy. Microscopy revealed extracellular amorphous and eosinophilic hyaline material which stained pink with Congo red and displayed green birefringence on polarized microscopy, leading to a diagnosis of amyloidosis. The results of the systemic workup were completely normal. A two-year follow-up period without any treatment disclosed no worsening of the condition. While calcification of nonvascular orbital lesions has often been regarded as suggestive of malignant disease, our case is a reminder that it can also be a characteristic presenting sign of orbital amyloidosis.