Swelling in the Gluteal region

A 70 years man presented with incapacitating left calf Claudication and swelling in the left gluteal region. Physical examination revealed a 10cm x 8cm palpable pulsatile mass over the left gluteal region with palpable left femoral pulse and absent popliteal pulse and ankle pulses.ABI was1.01 on right side and 0.6 on left side.C.T angiogram of the lower limbs was performed from lower abdominal aorta to both lower limbs ,Left lower limb showed a persistent sciatic artery aneurysm with a hypoplastic superficial femoral artery coursing medially and tapering as it proceeds to popliteal region. The trifurcatin arteries were patent. The arterial system on the right side were unremarkably normal. The PSA was ligated at the distal continuity using a medial popliteal approach. Femoro popliteal bypass using a 6mm PTFE graft was performed to restore distal flow to the lower limb .. Through a separate incision in the left lower abdomen , ligation of posterior division of internal iliac artery done after therapeutic embolisation. Post operatively the pulsatile mass reduced completely. The patient recovered with palpable peripheral pulses.A rare case, which presented as pulsatile gluteal swelling.