<prompt> A patient presented with local gigantism of the leg and increased pulsations of the lower limb veins. Most probable diagnosis isVaricose veinsAV fistulaBuerger diseaseTumour  <response>: The patient is having congenital AV fistula which has caused overgrowth of the leg. Aeriovenous fistula AVF AVF may be congenital or acquired by the trauma of a penetrating wound, or surgically created for renal dialysis Structural effect on veins - Veins are aerialised, they become dilated touous and thick walled. Physiological effects of fistula - Increased pulse pressure Increased systolic decreased diastolic Enhanced venous return result in Increased HR and Increased CO. Left ventricular enlargement and later cardiac failure may occur A congenital fistula in the young may cause overgrowth of limb. In the leg, indolent ulcers may result from relative ischemia below the sho circuit. Clinical signs A pulsatile swelling A thrill on palpation Continuous bruit on auscultation Nicoladonis sign or Branham sign - Pressure on the aery proximal to fistula causes the swelling to diminish in size, a thrill or bruit to cease, the pulse rate to fall and the pulse pressure return to normal. Ref : Bailey Love 25e p923 