Introduction

A metal-on-metal total hip arthroplasty pseudotumor is also known as aseptic lymphocyte dominant vasculitis-associated lesion or an alval lesion. Diagnosis involves obtaining a meta-subtraction MRI study in the setting of elevated serum metal ion levels, specifically cobalt and chromium. Patients may complain of gradual onset of symptoms or a sudden inciting pain in the groin. Some patients may be asymptomatic, but if they are symptomatic, may exhibit groin pain, and or a trendelenburg gait.