Primary localized amyloidosis presenting as diffuse amorphous calcified mass in both orbits: case report / Amiloidose primária localizada se apresentando como massa tumoral amorfa e calcificada em ambas as órbitas: relato de caso

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.

Amiloidose primária e localizada na órbita é rara. Relatamos o caso de paciente do sexo feminino, 63 anos que se apresentou com proptose bilateral e oftalmoplegia. A tomografia computadorizada mostrou uma massa infiltrativa amorfa e calcificada em ambas as órbitas enquanto que a imagem por ressonância magnética mostrou imagem heterogênea hipointensa ponderada em T2. Uma biópsia foi realizada por orbitotomia anterior. A microscopia revelou um material extracelular amorfo, hialino e eosinofílico que corou com vermelho Congo e mostrou cor verde birrefringente à microscopia com luz polarizada, levando ao diagnóstico de amiloidose. O resultado da investigação sistêmica foi inteiramente negativo. Um período de seguimento de dois anos sem qualquer tratamento não evidenciou piora da condição. Enquanto que a presença de calcificação de lesão não vascular da órbita frequentemente é considerada sugestiva de doençamaligna, o nosso caso serve para lembrar que pode também ser um sinal característico de amiloidose orbitária.

MR Imaging of the Orbital Apex: Anatomy and Pathology

The apex of the orbit is basically formed by the optic canal, the superior orbital fissure, and their contents. Space-occupying lesions in this area can result in clinical deficits caused by compression of the optic nerve or extraocular muscles. Evenvascular changes in the cavernous sinus can produce a direct mass effect and affect the orbitapex. When pathologic changes in this region is suspected, contrast-enhanced MR imaging with fat saturation is very useful. According to the anatomic regions from which the lesions arise, they can be classified as belonging to one of five groups; lesions of the optic nerve-sheath complex, of the conal and intraconal spaces, of the extraconal space and bony orbit, of the cavernous sinus or diffuse. The characteristic MR findings of various orbital lesions will be described in this paper.