not-yet-known not-yet-known not-yet-known unknown CASE HISTORY A 22-year-old female patient managed on continuous ambulatory peritoneal dialysis (CAPD) from two years before because she was in end-stage kidney disease following severe systemic lupus erythematosus. She displayed painful and persistent swelling, encompassing multiple fingers, hands, and feet during the preceding few months. PTH levels were between 247-430 pg/ml, according to KIDGO guideline goals [6], relating intermittent use of calcimimetics associated with significant and sustained serum PTH decrease, presenting less than 200 pg/ml despite cinacalcet being suspended for more than six months before. She was receiving the following dialysis prescription: total time: 10-hour / dwelling period: 2 hours / Concentration: Dextrose 2.5% / Inflow: 1.8 litres; maintaining high calcium-phosphorus product and severe hyperphosphemia despite high doses of calcium chelators. Given that previously described lesions appeared accompanied by those biochemical abnormalities formerly mentioned, hospitalisation was decided, describing in radiographies EC as BT in the proximal phalanges, metacarpals, and metatarsals (Figure 1).