Choroidal Melanoma With Optic Nerve Infiltration Presenting as Orbital Pseudocellulitis

Abstract

LEGEND A 60-year-old male presented with (Fig. A) right orbital cellulitis with no perception of light, shallow anterior chamber, mid-dilated and fixed pupil, cataract and intraocular pressure of 62 mm Hg. B-scan ultrasonography (Fig. B) revealed mushroom shaped intraocular mass with choroidal excavation. A final diagnosis of choroidal melanoma with orbital pseudocellulitis was made. The right globe was enucleated after the inflammation was controlled with intravenous corticosteroids. Systemic work-up revealed no evidence of metastasis. Cut section of the enucleated globe (Fig. C) revealed a peripapillary pigmented choroidal tumor. On histopathology, necrotic variant of choroidal melanoma with epithelioid cells was confirmed (Fig. D). The tumor was infiltrating the optic nerve 1 mm beyond the lamina cribrosa. Tumor emboli were noted focally in the scleral blood vessels. Resected end of optic nerve was free of tumor. In this case of choroidal melanoma, presenting feature of orbital pseudocellulitis and optic nerve tumor infiltration were the two unusual features. Orbital pseudocellulitis is a rare presenting feature of choroidal melanoma and can occur in cases with or without extraocular tumor extension. Orbital pseudocellulitis in choroidal melanoma could be related to extensive tumor necrosis or secondary glaucoma, which causes release of inflammatory mediators causing orbital inflammation that responds favorably to systemic corticosteroids. In this case, orbital pseudocellulitis subsided after 48 hours of intravenous corticosteroids. Optic nerve invasion is rare in uveal melanoma and is associated with poor prognosis. The risk factors for optic nerve invasion of choroidal melanoma are elevated intraocular pressure, nonspindle cell type, and juxtapapillary tumor location. All these features were noted in this case.