Bone histology in chronic kidney disease-related mineral and bone disorder.

A quantitative histological analysis of biopsied bone samples is currently regarded as the gold standard for a diagnosing procedure for bone diseases associated with chronic kidney disease-related mineral and bone disorder. Conventionally, "bone cell activities" and "bone mineralization" are applied as two independent assessment axes, and the histology results are classified into five categories according to these axes. Recently, a new bone histology classification system called the Turnover-Mineralization-Volume system, which applied "cancellous bone volume" as another major assessing axis, was advocated; however, both classification systems have many unsolved problems. Clinicians must realize the limitations in evaluating bone metabolism by bone histology. We will need to establish a new classification method for renal bone diseases independent of histological findings.