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Neuroradiology Case of the Week

Case 389

March 2009

Charles Hubeny, MD

Clinical Presentation: A 66-year-old man with history of metastatic melanoma presented with headache and slurred speech.

Imaging Findings: Intraconal mass lesion and hemorrhagic mass lesion in the brain (multiple other hemorrhagic brain lesions not pictured).

Diagnosis: Metastatic melanoma to the orbit

Discussion: Melanoma is a malignant tumor of the skin but can occur in the eye (uvea) and throughout the GI system. It is more common amongst males and Caucasians as well as groups that live in sunny climates. UVA and UVB exposure is the main contributor to melanoma development. The use of tanning beds has also been linked to the disease. Sun exposure at a younger age and blistering sun burns have a stronger association with melanoma. Sunscreen use does not protect from melanoma development. Some also may argue that sunscreen may increase the risk of getting this cancer.
     Treatment includes surgical removal. The sole effective cure is surgical resection of the primary tumor before it reaches greater than 1 mm of thickness. Other treatments include chemotherapy, immunotherapy, or radiation therapy for disseminated disease.
     The most common metastatic sites of melanoma in descending order are the dermis, lungs, liver, brain, bones, GI system, and kidneys. Metastasis to the orbit is rare. In the patient above the lesion is localized to the retrobulbar intraconal area. The differential for intraconal lesions includes lymphangioma, lymphoma, hematoma, metastasis, optic nerve lesions (glioma, meningioma, schwannoma, etc.), sarcoid, orbital pseudotumor, rhabdomyosarcoma, and vascular causes such as cavernous hemangioma and varix. The presence of numerous hemorrhagic lesions in the brain with the patient’s history limits the differential to favor melanoma.

References:

1. Grossman RI, Yousem DM. Neuroradiology: The Requisites. Philadelphia, PA: Mosby, 2003.
2. Cotran RS, Kumar V, Collins T, Robbins SL. Robbins Pathologic Basis of Disease. 6th ed., Philadelphia, PA. Elsevier Science. 2000.
3. Som PM, Curtin HD. Head and Neck Imaging, 4th ed. St. Louis: Mosby, 2003.