Epithelioid angiosarcoma at a non-functioning arteriovenous fistula site in a renal transplant patient.

Abstract

We present a case of biopsy-proven epithelioid angiosarcoma in an arteriovenous fistula (AVF). Angiosarcomas developing in non-functioning AVF in renal transplant recipients are rare clinical entities with poor prognosis. A 59-year-old male adequately immunosuppressed kidney transplant patient presented with pain and swelling at the site of a previously asymptomatic fistula. A duplex scan confirmed the presence of thrombosis present along the length of the AVF; however, in light of worsening pain and skin changes, an MRI scan was requested. This demonstrated a thrombosed brachiocephalic AVF and a more sinister appearing irregular segment infiltrating the underlying anterior compartment musculature with associated muscle oedema and internal irregular enhancement. A staging CT thorax showed indeterminate lymphadenopathy in the left axilla with no pulmonary lesions. Core needle biopsy of the primary lesion at the fistula site and subsequent biopsy of the axillary lymph nodes revealed metastatic angiosarcoma. A multidisciplinary decision was made to perform radical surgery with above-elbow amputation and simultaneous left axillary lymph node clearance. We focus on relevant imaging findings to facilitate early recognition of angiosarcoma, in particular, the importance of requesting urgent imaging of vascular access sites (functioning or not) in post-transplant patients presenting with swelling. Although rare, angiosarcoma is an important entity that should be considered in the differential diagnosis of soft tissue masses arising from a vascular access, especially in immunocompromised patients.