Dear Editor:

A 49 year old male presented with acute onset of left foot pain. On examination, the range of motion was preserved with signs of inflammation confined to the left first metatarsophalangeal joint.

Plain radiographs of the foot demonstrated soft tissue prominence surrounding the distal aspect of the left first metatarsal with an associated osteolytic lesion with faint calcifications (Panel A). Moderate edema within the marrow of the first metatarsal with juxta-articular cortical destruction and edema was depicted on MRI (Panel B). Although the imaging characteristics suggested gout, a fluoroscopic guided and ultrasound assisted image guided biopsy of the lesion was performed to exclude an infectious or malignant process. Stacks of light golden-brown needle shaped crystals (Panel C; Papanicolaou stain 500x) and numerous needle-shaped, birefringent, urate crystals (Panel D, Papanicolaou stain, Polarized, 300x), consistent with gout arthropathy were identified confirming the clinical suspicion allowing disease-specific therapy to be initiated.