Is unilateral breast enlargement always a sign of cancer?

Breast swelling is caused by many etiological factors, but should alert central vein occlusion in hemodialysis patients when the permanent vascular access is in the same arm. The swelling of the breast is caused by venous hypertension in the venous plexus draining the breast. Endovascular treatment relieves venous hypertension and related clinical signs. Additional diagnostic workup or invasive interventions such as a biopsy should be avoided in such patients, as diagnosis is straightforward with the presence of a functioning arteriovenous fistula in the same arm.