A raised fundus lesion at the level of the choroid has a high potential of being malignant since choroidal melanoma can appear clinically in many disguises. Final diagnosis may be made only after through investigations with ancillary techniques. We report on a case where--using fluorescein angiography--a suspected choroidal melanoma was diagnosed as having been simulated by a varix of a superior vortex vein ampulla. PATIENT: A 51-year-old woman was referred with the diagnosis of a choroidal melanoma in the upper periphery of the left fundus. Biomicroscopical retinal examination of the left eye revealed at upgaze a raised, slightly darkish lesion at the choroidal level in the peripheral 12 o'clock position. The lesion could not be visualised using the 3-mirror Goldmann contact lens and the area in question appeared flat. Fluorescein angiography showed evident dilatation of the superior vortex vein ampulla at upgaze giving rise to an elevation of both choroid and retina. CONCLUSION: Dilatation of the vortex vein ampulla is a rarely encountered lesion and is most often an incidental finding. Enlargement at up- or downgaze is thought to be evoked by kinking of the vein after leaving the eye through a long intrascleral passage in a very obtuse angle. This explains why the lesion could not be seen using the 3-mirror lens where the globe stays in the primary position. No treatment is indicated.