The forgotten appearance of metastatic melanoma in the small bowel.

Change log
Joslin, Emily 
McMorran, Victoria 
Hough, Caroline 
Palmer, Cheryl 

BACKGROUND: Melanoma is the most aggressive form of skin cancer, with a tendency to metastasise to any organ of the human body. While the most common body organs affected include liver, lungs, brain and soft tissues, spread to the gastrointestinal tract is not uncommon. In the bowel, it can present with a multitude of imaging appearances, more rarely as an aneurysmal dilatation. This appearance is classically associated with lymphoma, but it has more rarely been associated with other forms of malignancy. CASE PRESENTATION: We report a case series of three patients with aneurysmal dilatation in the small bowel (SB) confirmed to be due to metastatic melanoma (MM). All patients had non-specific symptoms; most times being attributed initially to causes other than melanoma. On CT the identified aneurysmal SB dilatations were diagnosed as presumed lymphoma in all cases. In two cases, the aneurysmal dilatation was the first presentation of metastatic disease and in two of the cases more than one site of the gastrointestinal tract was concomitantly involved. All patients underwent surgical resection with histological confirmation of MM. CONCLUSIONS: Recognition of unusual SB presentation of MM, such as aneurysmal SB dilatation, is important to expedite diagnosis, provide appropriate treatment, and consequently improve quality of life and likely survival of these patients. As the most common cancer to metastasise to the SB and as a known imaging mimicker, MM should remain in any radiologist's differential diagnosis for SB lesions with aneurysmal dilatation.

Journal Title
Cancer Imaging
Conference Name
Journal ISSN
Volume Title
Springer Science and Business Media LLC
Acknowledgements The authors acknowledge support from National Institute of Health Research Cambridge Biomedical Research Centre, Cancer Research UK (Cambridge Imaging Centre grant number C197/A16465), the Engineering and Physical Sciences Research Council Imaging Centre in Cambridge and Manchester and the Cambridge Experimental Cancer Medicine Centre. Funding source and conflicts of interest E.M.S is funded by NIHR Clinical Lectureship (Reference number: NIHR CL-2017-14-502) and is also supported by the Academy of Medical Sciences, the Wellcome Trust, the Medical Research Council (MRC), the British Heart Foundation, Versus Arthritis, Diabetes UK and the British Thoracic Society (Helen and Andrew Douglas bequest) Starter Grant award [SGL019\1007]. The views expressed are those of the authors and not necessarily those of the funders. No conflicts of interest to disclosure.