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Monocular Blindness as Presentation Manifestation of Neuroblastoma

A previously healthy 4-year-old patient was admitted with a 2-week history of extreme irritability with no apparent etiology on initial examination. Coincidentally, the child was noted to have intermittent strabismus involving the right eye. His visual acuity was 20/200 on the affected side with an afferent pupillary defect. On dilated direct ophthalmoscopy, a swollen optic disc was noted. There was no restriction of ocular movements. 
 
Magnetic resonance imaging of the brain and the orbits revealed a large, lobulated, contrast-enhancing mass in the region of the sphenoid bone (Figure 1A). The right optic nerve appeared to be completely surrounded by the mass (accounting for the edema of the optic disc on examination). 
 
 
 
Figure 1. 
 
A, 3.0T Magnetic resonance imaging of the brain and orbits. T1-weighted postcontrast image demonstrating an enhancing mass in the region of the sphenoid bone with involvement of the sphenoid sinuses and posterior ethmoid air cells. The mass involves the ... 
 
 
 
Meta-iodobenzylguanidine (MIBG) scan (using iodine-123-MIBG) showed evidence of diffuse metastases in axial and appendicular bones. The primary lesion was identified as a neuroblastoma involving the left adrenal medulla. Biopsy of the adrenal mass revealed round blue cells with scant cytoplasm and scattered Homer-Wright rosettes suggestive of neuroblastoma (Figure 1B). Cytogenetics revealed amplification of the Neuroblastoma MYC Oncogene (NMYC), which correlates with increased frequency of intracranial or orbital, liver, and lung metastasis.1 
 
Neuroblastoma—the most common extracranial solid tumor of childhood—consists of cells derived from the neural crest. Patients presenting with blindness often have stage IV disease. At the time of initial diagnosis, up to 18% of children will have metastases to the cranial bones/orbit.1 Neurologists who encounter optic disc swelling should entertain a broad differential diagnosis and consider early imaging to avoid potentially fatal pitfalls.