鎖骨遠位部に骨破壊を生じた長期透析患者の 1 例

We report a case of bone destruction of distal clavicle in a long-term dialysis patient. The patient was a 21-year-old male who had been undergoing dialysis for 16 years, developing abnormal mass of the right distal clavicle. Plain shoulder X-rays showed massive soft tissue calcification associated with osteolysis of the distal clavicle, suggesting dystrophic calcification due to renal osteodystrophy. T1-weighted MRI demonstrated mass lesion iso intensity, and T2-weighted MRI showed the low intensity area with small foci of high intensity. Focal curettage was performed suspecting local infection. Pathological diagnosis was hyperparathyroidism. Close inspection of systematic bone X-rays revealed ectopic calcification on the bilateral hip joint and very generalized loss of bone density, with relative increase in the density of the vertebral end-plates, which is the so called 'rugger jersey appearance'. Careful follow-up is necessary to examine systematic bone lesions in long-term dialysis patients.