Phalangeal cartilage with tophus on ultrasound and gross anatomy

The images are from a cadaveric specimen with tophaceous deposit over a proximal phalangeal joint.
(A) Ultrasound in transverse view of the phalangeal cartilage shows tophus (arrowhead) as a hyperechoic deposit of heterogenous echo texture with hypoechoic rim, located next to a double contour sign (arrow). The monosodium urate crystals (arrow) are seen as a fine superficial echogenic line (arrow) and the cartilage is the deeper thicker hypoechoic line (dashed arrow).
(B) Correlative gross anatomic photograph shows the tophus (arrowhead) and monosodium urate deposits (arrows) on the hyaline cartilage (dashed arrow).