Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) is a well-known risk factor for urolithiasis and nephrocalcinosis, wich are now less commonly reported due to an early detection of hypercalcemia by routine measurement of serum calcium. PHPT is most commonly caused by a single adenoma of the parathyroid gland. The incidence of multiglandular disease (MGD) range from 2.4–34%. In case of large tumor differential diagnosis is necessary to rule out malignancy.

Case report: We report the case of a 36 years old man presenting with multiple obstructive lithiasis in the left ureter with consecutive hydronephrosis. Biochemical evaluation revealed hypercalcemia (serum calcium=13.84 mg/dl, n.v.=8.6−10, ionizing calcium=5.97 mg/dl, n.v.=3.82−4.82) due to PHPT (PTH=565.7 pg/ml, n.v.=15−65, serum phosphate=1.7 mg/dl, n.v.=2.5−4.5, alkaline phosphatase=192 U/l, n.v.=40−129). In order to reduce calcium level the patient received bisphosphonate and calcitonine and, after ureteral stenting, diuretics and hydration. Ultrasound revealed a 5 cm tumor of the right inferior parathyroid gland, with necrotic areas, confirmed also by SPECT- CT. During surgery, beside the tumor, the hyperplasia of the other 3 parathyroid glands was observed. Right lobectomy with tumor, right superior and 50% of the left inferior parathyroid gland resection was performed. A reduction with more than 50% of PTH level was observed 10 minutes after tumor resection. The histopathological examination confirmed the hyperplasia including in the tumoral gland. The PTH level initially dropped off, but then rapidly raised around 150 pg/ml, maintaining this level more than 6 months, despite normal calcemia and then normalised. No recurrence of nephrolithiasis after surgery. There were insufficient criteria for MEN 1 syndrome.

Conclusions: Serum calcium level should be measured in all patients with urolithiasis. The preoperatory diagnose of MGD can be challenging. Elevated PTH levels can be observed after successful surgery as a transient phenomen.