Endocrine Abstracts

Introduction: Parathyroid adenomas with marked hypercalcemia need in most of cases surgical treatment. Calcimimetic treatment is usually a bridging therapy to correct hypercalcemia (in combination with other approaches, e.q. bisphosphonates). We describe case of conservative treatment in a patient in whom surgical therapy was not possible due to severe acute pancreatitis and where a high dose of calcimimetics led to clinical, laboratory and graphic remission with the possibility of discontinuation of treatment.

Case report: A 64-year-old lady was admitted to our hospital for severe acute pancreatitis, triggered with hypercalcemia in primary hyperparathyroidism (iPTH 740 ng/l; Ca 3.4 mmol/l). Hypercalcemia was corrected with intravenous bisphosphonate and during very complicated and prolonged disease (from July to November) with impossibility of surgery it was necessary to proceed to treatment with high dose of cinacalcet (up to 180 mg three times a day). Initial graphic examinations (sonography, CT) showed a probable 10mm adenoma of the right lower parathyroid gland; in the acute condition we did not perform functional imaging. After resolution of pancreatitis, ^99mTC MIBI scintigraphy was performed, but the enlarged parathyroid gland (with same size) appeared to be inactive. We gradually reduced the dose of cinacalcet while controlling calcemia and managed to discontinue the treatment within 6 months. Further scintigraphy one month after discontinuation of treatment showed no accumulation of the isotope. In the next two years, calcemia and PTH levels remained normal. Further scintigraphy showed a reduction parathyroid adenoma to 5mm (corresponding sonographic finding) and physiological isotope accumulation. The patient remains under follow-up in our endocrinology outpatient clinic (also for secondary - post-pancreatic diabetes requiring insulin therapy) and over the next six years, she continues to have physiological calcium metabolism with adequate parathyroid hormone levels, need for D-vitamin replacement and osteopenia.

Discussion: A case report of parathyroid apoplexy followed by hypocalcemia as a consequence of cinacalcet administration is described in the literature. It is not clear whether our patient’s case was a consequence of supramaximal treatment with cinacalcet or a result of a generally severe, months-long condition that could have led to ischemia of the adenoma. In any case, there was a remission of primary hyperparathyroidism lasting many years.