Uraemic tumoural calcinosis.

A 59-year-old Chinese patient had a history of endstage renal disease secondary to glomerulonephritis and underwent peritoneal dialysis. Nine years after initiation of dialysis, he developed an enlarging ‘tumour’ over his right wrist in the absence of antecedent trauma. Within 1 month of presentation, he was unable to use chopsticks because of the painful mass. At that time, his serum calcium and phosphate levels were 2.77 and 2.84mmol/l, respectively (calcium phosphate product 7.9mmol/l), with a serum intact parathyroid hormone level (iPTH) of 12 pg/l (normal range 0.07–0.56 pg/l). Alkaline phosphatase level was normal. Plain radiograph showed a large mass of encapsulated amorphous calcium phosphate around his right wrist joint (Figure 1A). Bone erosion into the radial aspect of the trapezium by metastatic calcification (Figure 2) was evident radiologically.