A 61-year-old man was hospitalized for paresthesias and renal insufficiency (creatinine clearance 24 ml/min) with proteinuria. Type 2 diabetes was diagnosed in 2003 and hypertension in 2007. Hypercalcemia (4.6 mM) with normal phosphorus level 1.23 mM was discovered with very high PTH levels (863 ng/l; N<78). MIBI scintigraphy localized a right inferior parathyroid tumour. No obvious sign favouring MEN1 was observed and no familial case was reported. After a short pamidronate treatment and hydration, surgery allowed to remove the tumour and a parathyroid carcinoma was diagnosed. Post surgery PTH levels decreased to about 100 ng/l. Two months later, a thyroid right lobectomy with lymph nodes dissection was performed. No invasion was found. One month later, PTH was still high 191 ng/l with serum calcium concentration 2.18 mM and phosphorus level 0.78 mM. No hungry bone syndrome was observed and 25-OH Vit D was in the low-normal range 40 nM. SestaMIBI scintigraphy and cervical ultrasonography were normal. Eight months later PTH was very high 419 ng/l with hypercalcemia 3.3 mM and low phosphorus levels 0.52. An 18 Fluoro-FDG PET scan was normal with no fixation on bones or lungs. Creatinine clearance was 54 ml/min. After bisphosphonate and hydration without major effect (calcemia 2.88 mM), cinacalcet was begun with titration: 30 mg BID one week, 60 mg BID three weeks. Calcium levels were slightly decreased at 3 mM with low phosphorus levels: 0.38; 0.45; 0.61 mM. Cinacalcet dosage is now increased to 90 mg BID and is presently well tolerated (no nausea or vomiting noticed). Treatment titration is still going on; a new sestaMIBI scintigraphy is planned. Though emergent, Cinacalcet seems promising to control hypercalcemia in parathyroid carcinoma. Actualization of our data will be given with genetic results of HRPT2.
03 - 07 May 2008
European Society of Endocrinology