Imaging of abdominal manifestations of melanoma

Despite an increasing incidence of melanoma in this country, innovative new therapies are allowing patients to receive aggressive experimental treatme nts. Diagnostic imaging remains crucial for tumor staging and for follow-up of patients being treated with these protocols. Because metastases occur i n the abdomen and pelvis in approximately 60% of patients, it is important to accurately identify all sites of tumor spread. A variety of imaging tech niques are used to image these patients, with CT currently being used for s taging purposes and to guide diagnostic biopsies. Other imaging techniques, such as MR, ultrasound, and fluoroscopy, are currently reserved for invest igating specific complications of melanoma, such as vascular invasion, hemo rrhage from a tumor, and small bowel involvement, including intussusception . Recently, whole body positron emission tomography (PET) imaging using 2-d eoxy-2-fluoro-D-glucose (FDG) has been shown to be highly accurate in asses sing patients with metastatic malignant melanoma. This review illustrates t he spectrum of manifestations of metastatic melanoma throughout the abdomen and pelvis, including solid organ, hollow lumen, and retroperitoneal invol vement, and demonstrates some of the typical and atypical manifestations th at may be identified.