Diffuse xanthogranulomatous pyelonephritis in children: an unrecognized variant

Xanthogranulomatous pyelonephritis in childhood has been thought to exist only in focal form. We encountered 2 cases of diffuse xanthogranulomatous pyelonephritis in children and have found 3 others reported in the literature, making it necessary to change this concept. The essential radiologic and pathologic differences between focal and diffuse xanthogranulomatous pyelonephritis are reviewed.