Intramedullary spinal cord metastasis of malignant melanoma:Two cases with rim signs in contrast-enhanced magnetic resonance imaging: A case report

Spinal cord metastasis of malignant melanoma is mostly caused by the invasion of the spinal cord by malignant melanoma. However, direct metastasis in the spinal cord is rare and difficult to diagnose accurately. A few diagnostically valuable findings of intramedullary spinal cord metastases (ISCMs) have been published. However, a highly specific finding of ISCMs of all carcinomas is the 'rim sign', which signifies the enhancement of the edge-dominant effect of the lesion in contrast-enhanced MRI. The objective of this case series was to examine the ratio of ISCMs of malignant melanoma with an indication of rim signs in contrast-enhanced MRI. The present report describes two cases of ISCMs of malignant melanoma in which the rim sign in contrast-enhanced MRI was useful for diagnosis.