Malignancies confined to disused arteriovenous fistulae in renal transplant patients: an important differential diagnosis.

BACKGROUND: Swelling in an arteriovenous fistula (AVF) is commonly caused by thrombosis, aneurysm and infection. However, due to the increased risk of malignancy after transplantation, this should also be considered. PATIENTS: We discuss 4 patients with malignancy confined to an AVF after renal transplantation presenting in a 2-year period. Angiosarcoma was diagnosed in 3 patients and the other had post-transplant lymphoproliferative disorder (PTLD). Angiosarcoma behaves aggressively and 2 of our patients died within 6 months of diagnosis. There are 6 previous cases and 5 died within 16 months of diagnosis. PTLD at AVFs has not been documented previously.
CONCLUSION: Malignancy at an AVF is a rare but important differential that can impact significantly on patient morbidity and mortality. Predilection for malignancy at an AVF is not understood. We review the literature and discuss possible aetiologies.