Primary Hyperparathyroidism From Ectopic Parathyroid Adenoma in a 12-Year-Old With Slipped Capital Femoral Epiphysis

Abstract

Primary hyperparathyroidism has been reported in pediatric patients presenting with slipped capital femoral epiphysis (SCFE), but never in patients with ectopic parathyroid adenoma. A 12-year-old boy with obesity and autism spectrum disorder presented with a limp and was found to have bilateral SCFE. Calcium was elevated to 12.3 mg/dL with parathyroid hormone (PTH) of 1191 pg/mL. Neck ultrasound revealed no parathyroid adenoma. He was discharged following bilateral surgical pinning with plans for outpatient workup. Repeat labs five days later demonstrated calcium had risen to 16.7 mg/dL. Tc-99m Sestamibi scintigraphy and CT scan revealed a 2.7 x 1.6 x 1.9 cm intrathymic mediastinal lesion. He underwent a thoracoscopic resection of the mass, and intraoperative PTH levels fell appropriately. Pathology revealed a parathyroid adenoma. Post-operatively, the patient developed hungry bone syndrome followed by normocalcemic secondary hyperparathyroidism which resolved with high-dose vitamin D supplementation. Primary hyperparathyroidism presenting as SCFE in a pediatric patient has been reported in thirteen previous cases. This is the first reported case of bilateral SCFE arising from an ectopic parathyroid adenoma. Thoracoscopic resection is a relatively new approach in pediatrics. Primary hyperparathyroidism can be associated with SCFE, especially bilateral, and should be considered in patients with traditional risk factors for SCFE. Pediatric patients with primary hyperparathyroidism and negative neck imaging should be further evaluated for ectopic parathyroid adenomas with nuclear medicine or cross-sectional imaging that includes the head, neck, and mediastinum. Thoracoscopic resection can be considered in pediatric patients with mediastinal ectopic parathyroid adenoma.

Primary hyperparathyroidism presenting as slipped capital femoral epiphysis; a patient assessment and literature review

“…In the literature, 11 cases are due to single parathyroid adenoma, whereas in one case, it is parathyroid carcinoma. In 11 cases of SCFE with primary hyperparathyroidism, only one case has ectopic mediastinal parathyroid adenoma (6).…”

Management of Atypical Slipped Capital Femoral Epiphysis

“…27 Low levels of vitamin D may also be seen. 28 These changes can manifest on radiographs or MRI as an abnormal widening or irregularity of the physis. 14 Late manifestations can also include osteitis fibrosa cystica/brown tumors.…”

“…29 The most common etiology of primary hyperparathyroidism is parathyroid adenoma. 28 It is particularly important for urgent endocrinology consultation in these patients as profound hypercalcemia can be life-threatening, with cardiac and neurologic manifestations. Correction of severe lab abnormalities should take precedence over surgery.…”

“…20 Less than 20 cases of primary hyperparathyroidism have been reported in the literature, with a majority of them presenting with bilateral SCFE. 28,30,31 For the cases presenting as unilateral SCFE, bilateral fixation is advocated given the risk of contralateral slip progression. 26,32 Copyright © 2023 JPOSNA® www.jposna.org…”

Pediatric Neuroendocrine Neoplasia of the Parathyroid Glands: Delving into Primary Hyperparathyroidism

“…On the contrary, postoperative hypocalcemia associated with normal (or high, but lower than the preoperative level) PTH, as described in hungry bone syndrome, was reported in a few cases/series [15,36,69,70]. For instance, a 14-year-old male who was admitted for digestive complaints and lethargy was detected to have a PTH excess-associated brown pelvic tumor, with remission following parathyroidectomy, accompanied by transitory starvation bone syndrome [71].…”