A patient with metastatic melanoma of the small bowel

We report the case of a 74-year-old man with metastatic melanoma of the small bowel. Melanoma metastasizing to the small bowel is a rare but well described presentation of the disease, detected clinically in only 2% to 5% of these patients. Its presentation is similar to other gastrointestinal tract tumors, with symptoms of abdominal pain or anemia prevailing. Recent studies have implicated the chemokine receptor CCR9 and its ligand CCL25 as signals that allow malignant melanoma cells to preferentially metastasize to the small bowel. Common imaging modalities used to detect these small bowel lesions include contrast-enhanced computed tomography (CT) scans and upper gastrointestinal series with small bowel follow-through. Given the low sensitivity of these modalities, newer helical CT scanners, ¹⁸F-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG PET)/CT, and capsule endoscopy are now being recommended to replace the older imaging techniques. Current treatment modalities include surgical resection, which has been shown to increase overall survival, and adjuvant immunotherapy, whose efficacy is currently being questioned. A review of the current literature describing this rare occurrence is included to compare with our patient's presentation, diagnosis, and management.