Case Report: Primary Duodenal Melanoma with Brain Metastasis.

Malignant duodenal tumors can be primary or secondary. Although the most common primary tumor involving the duodenum is an adenocarcinoma, primary malignant melanomas arising in the small intestine are exceedingly rare and remain a controversial clinical entity. In this report, we present a unique case of primary duodenal melanoma with brain metastasis managed successfully by surgical excision, stereotactic radiation, and adjuvant immunotherapy.