Choroidal pigmentation - a differential diagnosis.

Using only a few tests, it was possible to differentially diagnose a benign choroidal nevus with overlying medullation. Having revealed a flat retina with no apparent mass in the area, the ultrasound B-scan initially ruled out a choroidal malignant melanoma, choroidal hemangioma, metastatic tumor and a rhegmatogenous retinal detachment. Binocular indirect ophthalmoscopy and application of the Goldmann 3-mirror gonioscopy lens revealed that the lesion was not a retinal detachment. Due to the location of the lesion, disciform macular degeneration was also ruled out. Fluorescein angiography was the final test which aided in the definitive differential diagnosis, since it was characteristic of a choroidal nevus. Even though not all possible choroidal nevi need such an extensive work-up, occasionally specialized test can aid in the differential diagnosis of benign from potentially malignant lesions.