Malignant melanoma of gastrointestinal tract on 18F-FDG PET/CT: three case reports.

Primary malignant melanoma most frequently occurs in the skin. Melanoma affecting the gastrointestinal (GI) tract has been substantiated for lesions occurring in the esophagus, stomach, small bowel, and anorectum through multiple published reports, given the presence of melanocytes in these areas. Nevertheless, owing to the exceedingly low incidence of this disease, reports on its clinical features are few, and treatment approaches lack standardization. In this study, we present three cases of GI melanoma with imaging manifestations, emphasizing the pivotal role of ¹⁸F-FDG PET/CT in staging for GI melanoma. Establishing a definitive diagnosis of primary GI melanoma necessitates the exclusion of the possibility of metastasis from more prevalent primary sites. Advancements in molecular imaging technologies and the development of novel tracers provided significant promising methods for enhancing the diagnosis and management of melanoma, contributing to improved patient outcomes and overall disease management.