MRI of malignant melanoma of liver.

We report MR images of primary malignant melanoma of the liver. The tumor showed heterogeneously increased signal intensity on both T1- and T2-weighted images. After the administration of gadolinium-DTPA, the lesion presented irregular enhancement. Autopsy revealed a large black mass surrounded by fibrous tissue. The tumor consisted of atypical cells with melanin pigment, and had intratumoral degeneration, necrosis, and hemorrhage.