18FDG-PET/CT assessing the absence of cell viability and excluding metastatic disease in a case of necrotic choroidal melanoma.

PURPOSE

To report a case of choroidal melanoma in which the absence of 18FDG-positron emission tomography (PET)/computed tomography (CT) uptake in the whole body scan excluded the presence of any foci of metastases. Additionally, the PET/CT study correctly diagnosed the necrotic character of the lesion.

METHODS

A 76-year-old woman with neovascular glaucoma, and without vitreous or retina visualization, was studied by our ophthalmology service.

RESULTS

Ocular ultrasound showed an 18 × 16 mm vitreous exophytic image compatible with choroidal melanoma; magnetic resonance gave a 17 × 15 mm exophytic image, highly intense at T1 and hypointense at T2, with cystic and necrotic images after a contrast injection. An 18FDG-PET/CT study revealed a clearly hypometabolic lesion, representing absence of cell viability and excluding active melanoma cells. No other uptake lesions were detected at the whole-body PET/CT scan, assuming the absence of extraocular metastases. The eye was enucleated, and the pathology study showed a 16 × 15 mm necrotic choroidal melanoma.

CONCLUSIONS

The 18FDG-PET/CT study correctly depicted the necrotic character of the choroidal melanoma and was able to exclude other foci of metastases.