Classic and anomalous standardized A-scan patterns of choroidal nevi elevated up to 3.5 mm

High internal reflectivity and a predominantly irregular structure on standardized A-scan were the classic acoustic features encountered at first examination in nine patients with unilateral ophthalmoscopic evidence of choroidal nevus elevated from 1.6 to 3.5 mm. In all patients but one with a 3.5 mm elevated nevus, periodic fluorescein angiography and automated perimetry findings were consistent with the diagnosis of choroidal nevi located at the posterior pole or in the mid periphery. Slight or no growth was observed echographically during the follow-up (seven months to seven years) except in one eye with a; solid pigmented lesion which progressively grew 1 mm and showed low reflectivity without spontaneous vertical movements or evidence of melanoma at ancillary examinations. In two other eyes the internal reflectivity of the choroidal nevus decreased gradually from high to medium. The differentiation between choroidal nevus and melanoma with standardized echography and the existence of a possible histologically intermediate lesion ('nevoma') are discussed.