Metastatic calcifications in a gouty tophus. Magnification of an Xray of the feet showing bulging and densification of the subcutaneous tissue in the metacarpophalangeal joint of the hallux, with small foci of calcification, corresponding to a gouty tophus. There are also signs of crystal arthropathy and erosion of cortical bone, especially in the first metacarpophalangeal joint on the left.