Intra-axial brainstem malignant melanoma mimicking cavernous angioma--case report.

A 41-year-old female presented with repeated pontine hemorrhage. Magnetic resonance imaging showed the pontine hemorrhage as a heterogeneously enhanced mass mimicking cavernous angioma. The mass lesion was removed via a midline suboccipital approach. Histological examination showed malignant melanoma cells. No cutaneous lesion was found and positron emission tomography found no abnormalities. Our presumptive diagnosis was primary intra-axial brainstem malignant melanoma. The possibility of malignant melanoma should be considered in patients with intra-axial brainstem lesion associated with repeated hemorrhages.