Occult foreign body simulating a choroidal melanoma with extrascleral extension.

A 62-year-old man was noted on routine examination to have a dark lesion in the peripheral fundus of the right eye and a corresponding dark scleral mass. The lesion was initially suspected to be a choroidal melanoma with extrascleral extension. The patient denied having ocular trauma. Orbital x-rays and ultrasonography, however, demonstrated the lesion to be an occult transcleral metallic foreign body. An occult foreign body should be considered in the differential diagnosis of a small choroidal or ciliary body melanoma with extrascleral extension.