Dorsal midbrain syndrome from a ring-enhancing lesion

Area of Science:

• Neurology
• Oncology
• Radiosurgery

Background:

• Dorsal midbrain syndrome is rarely caused by a single ring-enhancing lesion.
• Malignant melanoma can metastasize to the brain, presenting as solitary lesions.

Observation:

• A 60-year-old man presented with eye movement and pupillary abnormalities indicative of dorsal midbrain syndrome.
• Neuroimaging revealed a solitary ring-enhancing lesion in the right midbrain and thalamus.
• A history of a right groin mass was identified, later diagnosed as malignant melanoma.

Findings:

• The intracranial lesion was presumed to be a metastatic melanoma.
• The patient was treated with stereotactic radiosurgery for the solitary brain lesion.

Implications:

• This case highlights the importance of considering metastatic melanoma in the differential diagnosis of solitary ring-enhancing brain lesions.
• Stereotactic radiosurgery can be an effective treatment for solitary metastatic brain lesions.
• Further discussion on the diagnosis and management of solitary midbrain lesions is warranted.