Secondary hyperparathyroidism, calcium disorders, and brown tumors after renal replacement therapy

An extreme case of secondary hyperparathyroisism in a 35-year-old male patient after renal transplantation is shown with development of a brown tumor in the left os ileum. After parathyroidectomy it came to a regression and a calcification of the brown tumor. Although in the last decades great progress has been made concerning renal transplantation therapy, secondary hyperparathyroidism (sHPT) is still of major clinical importance in patients with chronic renal failure and even in transplanted patients, especially in the first year follow-up post transplantation. sHPT demineralizes bone structure via enhanced osteoclastic activity and can lead to osteofibrosis and in severe forms to brown tumor manifestations. On the other hand, defective kidneys are not able to synthesize sufficiently active vitamin D3 metabolites. This can result in osteoidosis and various forms of osteomalacia. Recently, a change in the wide spectrum of renal osteodystrophy in forms of adynamic bone disease and low turnover lesions are frequently observed. However, changes of parathyroid gland function in sHPT in renal insufficiency or in renal allograft recipients followed by adynamic bone disease indicate the central role in avoiding bone disease in these patients.