Ann Pediatr Endocrinol Metab.  2020 Sep;25(3):187-191. 10.6065/apem.1938172.086.

A case of primary hyperparathyroidism due to an intrathymic ectopic parathyroid adenoma in a 15-year-old boy

• Seo Y
• Song K
• Choi HS
• Suh J
• Kwon A
• Chae HW
• Kim HS

• KMID: 2507562
• DOI: http://doi.org/10.6065/apem.1938172.086

Abstract

Hypercalcemia due to primary hyperparathyroidism (PHPT) is uncommon in children. PHPT is typically caused by a single parathyroid adenoma. Ectopic parathyroid adenomas account for 6%–16% of all parathyroid adenomas and are rare in children but should be considered in cases that present with hypercalcemia. We report the case of a 15-year-old boy with PHPT due to an intrathymic ectopic parathyroid adenoma. Neck ultrasonography and Tc-99m-sestamibi (MIBI) scanning with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed ectopic parathyroid adenoma in the thymus. Video-assisted thoracoscopic surgery was performed to remove the ectopic parathyroid adenoma. Pathology showed intrathymic ectopic parathyroid adenoma. After surgery, the patient’s serum calcium level immediately normalized. Intact parathyroid hormone (iPTH) and alkaline phosphatase levels returned to normal ranges within 3 months. Delayed diagnosis of PHPT can cause end-organ damage; a timely diagnosis is especially critical to preserve bone and renal function. If ectopic parathyroid adenomas are well localized in preoperative imaging evaluation and intraoperative iPTH level decreases after resection, ectopic parathyroidectomy without bilateral neck exploration may be performed to avoid unnecessary morbidity.

Keyword

Primary hyperparathyroidism; Hypercalcemia; Ectopic parathyroid gland; Parathyroid adenoma; Child

Figure

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  Fig. 1. Long-bone radiographs were recorded yearly. This 1-year follow-up radiograph (B) shows increased right genu valgum (white arrow) compared to that of the previous year (A).

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  Fig. 2. Skull (A) and hand radiographs (B) indicate low bone density.

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  Fig. 3. An ectopic parathyroid adenoma is detected in the prevascular region by 99mTc-sestamibi scanning (A, black arrow) and single-photon emission computed tomography/computed tomography (B, white arrow).

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  Fig. 4. The gross appearance of an ectopic parathyroid adenoma. A well-demarcated mass 2.9 cm × 1.5 cm (black arrow) in size located within the thymus.

Reference

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