Clinical Quiz #4:
Clinical Quiz 4
A Caucasian 15.5 year-old girl is referred for a voluminous and rapid enlarging swelling in the root of the left thigh causing pain and limping. The mass seems to have grown within three months, with no obvious initiating event (except one shot of oral native vitamin D supplementation a few weeks before because of a low calcium diet as assessed by her GP, and following the French guidelines for vitamin D supplementation in teenagers), until a diameter of 15 centimeters.
The young girl has no significant medical or surgical past. There is no consanguinity, and no significant familial history is reported.
From a biochemical point of view, circulating calcium, phosphate, creatinine, total alkaline phosphatase, 25-D, 1-25D and PTH levels are respectively: 2.5 mmol/l, 2.8 mmol/L, 53 µmol/l, 54 IU/l, 63 nmol/L, 174 pg/mL (local normal range 19.6-54.3 pg/ml) and 4 ng/l (local normal range 15-65 ng/l). Renal tubular reabsorption of phosphate (TRP) is 90%.
Q1. What is your diagnosis?
Q2. Which one of the following therapeutic managements is NOT appropriate?