A patient presented with local gigantism of the leg and increased pulsations of the lower limb veins. Most probable diagnosis is :

The patient is having congenital AV fistula which has caused overgrowth of the leg. Arteriovenous 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 arterialised*, they become dilated tortuous 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 short circuit. Clinical signs A pulsatile swelling* A thrill on palpation* Continuous bruit on auscultation* Nicoladonis sign' or Branham sign* → Pressure on the artery 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.