A malignant melanoma and a melanin-pigmented tumor, both showing spontaneous intracerebral hemorrhage, were reported. A definite diagnosis of melanoma was made almost exclusively by histological examination of tumor tissue obtained at operation or autopsy. A search for primary tumor foci was performed in both cases before and after death. No extracerebral melanomas were found.Thus, these cases can safely be regarded as primary cerebral tumors.
In the present paper two assumptions were made. One assumption concerning spontaneous intracerebral hemorrhage from melanomas is that tumor cells release a chemical factor which causes the formation of fenestrate and subsequent hemorrhage. Another assumption concerning malignant changes of melanoma cells is that malignant change is influenced by genetic factors.