ESPE Abstracts

Background: Hypercalcemia, with hyperparathyroidism in children, is a very rare disease. The symptoms of hypercalcemia in children present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. Hyperparathyroidism in children is induced from genetically malignant or benign parathyroid adenoma.

Case: The case is a 12-year-old boy who had no significant medical history. He visited the hospital due to abdominal pain and mild fever. The symptoms were spontaneously diminished, but his blood test showed hypercalcemia with a level of 12.0 mg/dL. Intact PTH was 136 pg/mL, urine Ca/Cr ratio was 0.35 mg/dL, and urine calcium excretion rate was 1.4%. Thyroid ultrasound showed a 6.6 × 5.6 × 4.3 mm hypoechoic mass lesion in the lower left lobe of thyroid gland. The 99mTc-MIBI scintigraphy showed an abnormal accumulation that were nodular lesion in the lower left lobe of the thyroid gland. The contrast-enhanced CT scan of the kidney showed no hydronephrosis or stones. His parents showed no hypercalcemia or elevation of intact PTH. Parathyroidectomy was performed two months after detection of hypercalcemia. He was pathologically diagnosed with parathyroid adenoma. His calcium level was within the normal range after surgery, and no signs of hypercalcemia. Genetic testing revealed no variation in MEN1, CDKN1B, RET, CASR, GNA11, AP2S1, CDC73, and GCM2 genes.

Discussion: Hyperparathyroidism is improved after parathyroid adenoma in children is usually operated as a parathyroidectomy. However, exiting kidney stones was not improved by surgery. Therefore early diagnosis and treatment of hyperparathyroidism are crucial in children. The patient showed asymptomatic of primary hyperparathyroidism, and it is rare condition. This case without symptoms was incidentally diagnosed. Parathyroid adenoma in adults is a common cause of hyperparathyroidism. Meanwhile, multiple endocrine neoplasia (MEN) is the most frequent cause of hyperparathyroidism in children, accounting for over 90%. This case was diagnosed with non-genetical primary parathyroid adenoma.

Conclusion: MEN is most frequent cause of hyperparathyroidism in children, however, this young case with hyperparathyroidism was not MEN genetically. Genetic testing should be performed if hypercalcemia and/or parathyroidoma is found even in asymptomatic patients.