The "Knapp-Ronne" type of malignant melanoma of the choroid. A haemangioma-like melanoma with a typical clinical picture. So-called "preretinal malignant choroidal melanoma".

Five cases of a rare type of malignant melanoma of the choroid with a typical clinical and histopathological picture are reported. This tumour is characterized by it location near the optic disk,its early growth through the retina, its structure with bloodless and blood-filled cavernous spaces, and its manifestation by a massive haemorrhage into the vitreous. "Historical" cases are mentioned, showing that this rare tumour, occurring in about 1:250 of malignant melanomas of the choroid, has a Scandinavian tradition. The clinical and histopathological details are discussed.