LAUSR

Perinephric abscess is an accumulation of pus in the perinephric space.1 It frequently occurs as a secondary event to upper tract urosepsis, usually in relation with an infective staghorn stone.1 Clinical presentation of perinephric abscess is notoriously silent. Therefore, diagnosing perinephric abscess will be difficult without the aid of imaging.2 On the other side, malignant tumors with extra renal extension, perinephric hematoma, and urinoma may appear similar to perinephric abscess on imaging studies.3 Thus, a thorough examination should be performed in diagnosing perinephric abscess. We describe an unusual case of chronic pyelonephritis with perinephric abscess in 64-year-old man diagnosed after showing non-specific clinical presentation, conflicting laboratory results and unusual imaging findings.