A 78-year-old female presented with a 5-day history of blurred vision in the right eye, periocular pain, swelling, and photophobia. Past medical history was unremarkable except for recent bronchoscopy and transbronchial biopsy for a suspicious pulmonary nodule. The histopathology and immunohistochemistry confirmed the diagnosis of malignant melanoma.
On ophthalmological examination, visual acuity in her right eye was reduced to hand movements only and in her left eye it was 6/6. Slit lamp examination of her right eye showed intense inflammatory activity in the anterior chamber with a hazy view of the fundus. The pupil was poorly dilated due to almost 360  of posterior synechiae. B-scan of the posterior segment revealed vitreous opacities and dense condensations on the posterior vitreous face. Clinical diagnosis of possible endophthalmitis or pseudo tumor was made. As pulmonary nodule biopsy performed a week earlier showed malignant melanoma, choroidal melanoma was included in the differential diagnosis.
Urgent computerized tomography (CT) and magnetic resonance imaging (MRI) examinations were organized. Contrast-enhanced CT showed marked enhancement of the uveal tract on the right with preseptal edema and lateral thickening of the orbital septum (Figure 1), however, there was no retrobulbar fat stranding or posterior chamber abscess detected. Fluid attenuation inversion recovery (FLAIR) axial images demonstrated a definite signal change in the right vitreous chamber and a high signal subchoroidal effusion was seen (Figure 2A). Diffusion-weighted imaging (DWI) and apparent diffusion coefficients (ADC) were the key sequences showing restricted diffusion within the posterior chamber suggestive of subchoroidal abscess or effusion. Effusion was seen as a linear high signal within the right globe laterally extending up to the level of the optic nerve head (Figures 2B and C). The ADC value from the abscess measured 602 x 10-6 mm2/s in comparison to the central portion of 2650 x 10-6 mm2/s, implying true restriction. On postcontrast T1 fat saturated images, diffuse enhancement of the thickened sclera and the entire uveal was identified (Figure 3). Also seen was extension of this inflammatory process into the orbital septum as well as the extra-ocular muscles with marked thickening of the right lateral rectus muscle which also enhanced with contrast. The extraconal inflammatory change was localized more in the superolateral part of the right orbit. Recent diagnosis of melanoma from a pulmonary nodule caused a diagnostic dilemma and ocular melanoma or melanoma metastases were included in the initial differential diagnoses. MRI immensely helped in narrowing the differential diagnosis as there was no T1 bright lesion seen in the choroid to suggest melanoma.
Cytology from the initial vitreous aspirate did not yield malignant cells and subsequent cultures were negative. Blood tests showed moderate neutrophilia of 8.2 x 109/L, ESR of 20 mm/hour, and a normal serum ACE level of 35 U/L. Quantiferon TB Gold, VDRL, and blood cultures were also negative. Toxoplasmosis testing showed IgG reactivity with IgM nonreactivity. Culture from a repeated vitreous aspirate sample grew S. apiospermum. Antifungal susceptibility testing showed sensitivity to itraconazole and voriconazole with a minimum inhibitory concentration (MIC) of 0.5 mug/mL and 0.25 mug/mL, respectively. The patient was then started on a 6-month regimen of oral voriconazole. Despite therapy, patient's vision showed no improvement and vision remained restricted to hand movements only at the 12-month follow-up.