BACKGROUND: The aim of this article is to illustrate the possible applications of (18)F-fluorodeoxyglucose positron emission tomography/computer tomography ((18)F-FDG PET/CT) in chronic extremity lymphedema and its complications.

METHODS AND RESULTS: (18)F-FDG PET/CT findings in a rare case of Stewart-Treves Syndrome (STS), angiosarcoma secondary to chronic extremity lymphedema, are presented. Lymphedema of the extremities is a debilitating disease characterized by chronic swelling due to interstitial edema caused by insufficient lymphatic drainage capacity. Progression with skin thickening, subcutaneous fibrosis, and increased adipose tissue volume is common. Chronic inflammation has been suggested as a key pathophysiologic component. STS is a rare complication with a very poor prognosis; however, early diagnosis and radical treatment is associated with increased survival. Thus, accurate pretreatment staging is paramount. (18)F-FDG PET/CT is highly sensitive in detecting increased glucose metabolism as seen in many types of cancer and inflammation. The role of (18)F-FDG PET/CT in the management of lymphedema and its complications has to our knowledge yet to be described. This case documents high (18)F-FDG uptake in STS, but is at the same time an example of the low specificity of this imaging modality.

CONCLUSIONS: We suggest that (18)F-FDG PET/CT has the potential to become an important tool in the staging and treatment planning of Stewart-Treves syndrome. Furthermore, (18)F-FDG-accumulation may be a sensitive tool in detecting low grade inflammation in the skin and subcutis, which has been suggested to cause tissue remodeling in lymphedema progression. However, further studies are needed to elucidate this theory.