Ann Pediatr Endocrinol Metab.  2019 Sep;24(3):195-198. 10.6065/apem.2019.24.3.195.

Primary hyperparathyroidism versus familial hypocalciuric hypercalcemia: a challenging diagnostic evaluation in an adolescent female

• Tosur M
• Lopez ME
• Paul DL

• KMID: 2460767
• DOI: http://doi.org/10.6065/apem.2019.24.3.195

Abstract

Primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcemia (FHH) have significantly different treatment approaches, so physicians must be careful to differentiate these 2 diseases. Herein, we report a 14-year-old female who presented with symptomatic hypercalcemia (12 mg/dL; reference range, 9.2-10.7 mg/dL), elevated intact parathyroid hormone (iPTH) (236 pg/mL; reference range, 9-69 pg/mL), and vitamin D deficiency (6 ng/mL; reference range, ≥ 20 ng/mL). On numerous occasions, her 24-hour urine calcium was more than 4 mg/kg/day, consistent with PHPT, but her fractional excretion of calcium on 24-hour urine collection was consistently below 1%, in line with FHH. ⁹⁹mTc-Sestamibi scan failed to detect any abnormalities. However, a 4-dimensional computed tomography scan of the neck revealed a right superior parathyroid adenoma which was excised with a focused parathyroidectomy. Although the patient's calcium and iPTH levels normalized, her nonspecific symptoms persisted. This case illustrates both the challenges of differentiating PHPT from FHH and the limitations of a first-line imaging tool in identifying a parathyroid adenoma.

Keyword

Hypercalcemia; Primary hyperparathyroidism; Familial hypocalciuric hypocalcemia; Parathyroid adenoma; Parathyroid hormone

MeSH Terms

Adolescent*
Calcium
Female*
Humans
Hypercalcemia*
Hyperparathyroidism, Primary*
Neck
Parathyroid Hormone
Parathyroid Neoplasms
Parathyroidectomy
Reference Values
Urine Specimen Collection
Vitamin D Deficiency
Calcium
Parathyroid Hormone

Figure

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  Fig. 1. Four-dimensional computed tomography scan of the neck revealed a right superior parathyroid adenoma (black arrow) and salivary glands (white arrow) in coronal (A) and transverse (B) images.

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  Fig. 2. Pre- and postoperative calcium and intact parathyroid hormone (iPTH) trends in parathyroid adenoma.

Reference

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