A rare cause of flank mass: psoas abscess due to extensive primary thoracolumbar tuberculous spondylodiskitis.

Psoas abscess secondary to tuberculous spondylodiskitis is usually a complication of thoracolumbar vertebrae disease. The psoas abscess may be difficult clinically to diagnose because of its rarity, insidious onset of the disease, and nonspecific clinical presentation. We report multidetector CT and MR imaging findings of a psoas abscess secondary to primary tuberculous spondylodiskitis of the spine from the T3 to L2 vertebrae, which presented as a flank mass.