Primary hyperparathyroidism masquerading as rickets: diagnostic challenge and treatment outcomes

Vitamin D Hydroxylation-deficient Rickets Type 1A Misdiagnosed as Normocalcemic Primary Hyperparathyroidism

Vitamin D hydroxylation-deficient rickets type 1A is an autosomal recessive disorder caused by pathogenic variants in CYP27B1 gene, which encodes for 1α-hydroxylase, the enzyme responsible for the conversion of 25-OH vitamin D into its active form 1,25(OH)2 vitamin D. We report the case of a 3-year-old female Mexican patient with growth retardation and progressive bone deformity, whose laboratory studies showed 25-OH vitamin D deficiency, a normal serum calcium and an elevated intact parathyroid hormone level that remained high despite calcitriol, cholecalciferol, and calcium supplementation. 99mTc sestamibi gammagram showed findings suggestive of parathyroid hyperplasia. Bone histomorphometry showed an image consistent with hyperparathyroidism without findings of osteomalacia, so normocalcemic primary hyperparathyroidism was suspected and a subtotal parathyroidectomy was performed, with the patient developing postoperative hypoparathyroidism. When she arrived at our clinic at age 18 years, she showed calcium- and calcitriol-dependent hypocalcemia, with secondary hyperparathyroidism and low levels of 1,25(OH)2 vitamin D in the absence of a 25-OH vitamin D deficiency, reflecting a defect in 1α-hydroxylation. Molecular testing revealed compound heterozygous variants in CYP27B1 gene. This is the first reported case of an inherited disorder of vitamin D metabolism that was diagnosed and surgically treated as primary hyperparathyroidism.

Primary hyperparathyroidism in an adolescent presenting with genu valgus progressing to extensive bone disease; a case report

BACKGROUND

Primary hyperparathyroidism which is rare in adolescents presents commonly with non-specific symptoms and systemic complaints. Though there are few reported cases of genu valgus, genu valgus progressing to extensive bone disease despite mildly elevated calcium had not been reported before.

CASE PRESENTATION

A 12-year-old male had been evaluated for bilateral (left > right) genu valgus and short stature. Serum calcium and phosphate levels had been normal. X-ray of the femora and pelvic bones had not shown additional abnormalities. Valgus deformity progressed despite left femoral plating, and a left distal femoral medial closed wedge osteotomy had been performed at 15 years. Plain imaging at that time had shown localised osteopaenia. At the age of 17 years, he developed multiple fragility fractures of his left hip rendering him wheelchair-bound. Further evaluation revealed a serum PTH level of 2571 (10-65) pg/mL with calcium of 2.82 (2.2-2.6) mmol/L and inorganic phosphate of 1.7 (2.2-4.7) mg/dL. The lumbar spine DXA scan showed a Z-score of -5.8. A left parathyroid adenoma was localised and there was evidence of hyperparathyroid bone disease including brown tumours. He underwent left parathyroidectomy and left thyroid lobectomy after which his PTH level dropped to 4.03 pg/mL. He developed hypocalcaemia which was managed successfully with calcium and alfacalcidol replacement.

CONCLUSIONS

Primary hyperparathyroidism can present with genu valgus in adolescents. Initial normocalcaemia which could be due to concomitant vitamin D deficiency could mask this leading to delayed diagnosis until severe irreversible bone disease ensues.

The spectrum of manifestations of primary hyperparathyroidism in children and adolescents

INTRODUCTION

Primary hyperparathyroidism (PHPT) is a rare disease in children and adolescents. Early recognition of this disease is important to prevent significant morbidity and mortality.

MATERIAL AND METHODS

We included 10 consecutive patients with PHPT aged 14 to 19 years of age and followed-up prospectively upto one year after parathyroidectomy.

RESULTS

Our cohort included 6 females and 4 males. The mean age of the patients was 16.7 ±1.8 years. The symptoms at presentation were musculoskeletal pain (90%), bone deformity (50%), fracture (30%), proximal myopathy (40%), renal stones (50%), reflux symptoms (40%), and pancreatitis (30%). The mean serum calcium was 3.1 ±0.5 mmol/l, mean serum inorganic phosphorus was 0.9 ±0.3 mmol/l and median serum alkaline phosphatase (ALP) was 1911.5 IU/l (IQR: 522.7-5702.3). The median serum intact parathyroid hormone was 133.5 pmol/l (IQR: 69.5 -178.7) while serum 25(OH)D was 47.7 nmol/l (IQR: 23.7-72.7). Hypercalciuria was observed in 7 patients. Hungry bone syndrome was observed in 4 (40%) patients after surgery. Typical parathyroid adenoma was found in 9 (90%) patients while one patient had atypical adenoma with high mitotic index. After one year of surgery, all patients had significant improvement in clinical and biochemical parameters with persistence of residual bone deformities.

CONCLUSIONS

Our study showed the spectrum of manifestations of PHPT in children and adolescents and outcomes of parathyroidectomy till one year. Long-term follow-up studies with bigger cohorts are required to understand the true nature of the disease in children and adolescents.

Bilateral Genu Valgum in an Adolescent with Primary Hyperparathyroidism: A Case Report and Review of Literature

Primary hyperparathyroidism in children and adolescents is rare and often symptomatic at presentation. A 15-year-old bo presented with bilateral genu valgum for two years. Biochemical results were consistent with primary hyperparathyroidism Calcium levels normalized two months after removal of a left inferior parathyroid adenoma.

Pediatric Primary Hyperparathyroidism: Experience in a Tertiary Care Referral Center in a Developing Country Over Three Decades

BACKGROUND

There is limited experience in managing pediatric primary hyperparathyroidism (PHPT). The aim of this study was to analyze the clinical presentation and outcome of surgery in children with PHPT managed at a tertiary referral center.

METHODS

This retrospective study (September 1989-August 2019) consisted of 35 pediatric PHPT patients (< 18 years) who underwent parathyroidectomy. Clinico-pathologic profile and outcome were noted.

RESULTS

The mean age of cohort was 15.2±2.9 years and girls outnumbered boys (M:F = 1:1.9). Familial and symptomatic disease was noted in 8.5 and 94.3% cases, respectively. Skeletal manifestations (83%) were the commonest followed by renal (29%). Fifty-four percent children had skeletal fractures, and 23% were bed-ridden. Among rare manifestations, hypercalcemic crisis, recurrent pancreatitis and stigmata of rickets were observed in 2.8, 11.4 and 14.2% children, respectively. Mean calcium concentration was 12.1 ± 2.0 mg/dl and PTH 91.8 ± 66.5 pmol/L. The sensitivity of preoperative imaging in parathyroid localization was 91.4%. Minimally invasive parathyroidectomy (MIP) was performed in 40% cases. Parathyroid adenoma was observed in 91.4% patients, whereas remaining had hyperplasia. Thirty-four percent suffered from Hungry bone syndrome in postoperative period. The cure rate following primary surgery was 97%. One child with persistent PHPT had successful re-operation. Median follow-up was 5 (1-17) years, and no recurrence or familial disease was revealed during this period.

CONCLUSION

Majority of pediatric patients present with symptomatic PHPT. Despite relatively high incidence of familial disease select pediatric patients can undergo successful MIP.

PHPT Masquerading as Rickets in Children and Presenting with Rare Skeletal Manifestations: Report of Three Cases and Review of Literature

Primary hyperparathyroidism (PHPT) is an uncommon condition in children and adolescents. However, rapid growth spurt during puberty may result in unmasking and development of certain skeletal manifestations of PHPT. We present three cases of PHPT associated with rare skeletal manifestations of rickets. All three patients had radiological evidence of rickets with primary hyperparathyroidism. All the three patients had single gland adenoma. Literature is sparse regarding reversal of features of rickets following parathyroidectomy. In all three patients of our series, there was a complete resolution of bone/joint pain. However, in two children only the genu valgum persisted but their growth was normal and they had no proximal muscle weakness. In another child multiple corrective surgeries were done to correct the deformities.

Primary hyperparathyroidism in Chinese children and adolescents: A single-centre experience at Peking Union Medical College Hospital

OBJECTIVE

Primary hyperparathyroidism (PHPT) in children is thought to be extremely rare. Our study aimed to summarize the clinical characteristics and the molecular genetics in patients with paediatric PHPT in China.

DESIGN

Retrospective observational study.

METHODS

A total of 59 paediatric PHPT patients (onset age <18 years) admitted to Peking Union Medical College Hospital from 1975 to 2015 were retrospectively identified. A group of 118 adult PHPT patients who presented during the same period were selected for comparing clinical characteristics between the two groups. Germline mutation analyses of the MEN1, CDC73, RET, CDKN1B and CaSR genes were performed in 24 patients.

RESULTS

Only one paediatric patient (1.7%) with PHPT was asymptomatic. Bone involvement, urolithiasis, acute pancreatitis and hypercalcaemic crisis were present in 86.4%, 39.0%, 6.8% and 10.2% of cases, respectively. Paediatric PHPT presented more commonly with rickets/osteomalacia compared to adult PHPT. Fifty-seven paediatric patients underwent surgery. Adenoma, hyperplasia, atypical adenoma and carcinoma occurred in 80.7%, 10.5%, 7.0% and 1.8% of cases, respectively. Of the 24 paediatric patients screened for genetic mutations, two patients were found to carry MEN1 mutations and six were found to carry CDC73 mutations. The mutation rate was 22.2% (4/18) in sporadic patients.

CONCLUSION

Unlike adults with PHPT, most paediatric PHPT were symptomatic. Rickets/osteomalacia was more common in paediatric patients than in their adult counterparts. Paediatric PHPT patients can be treated successfully with surgical intervention. Genetic screening of the MEN1 and CDC73 genes for mutations should be recommended in paediatric patients due to a relatively high mutation rate.

A case report of spontaneous rupture of the quadriceps tendon

Spontaneous quadriceps tendon rupture is a rare occurrence in patients with primary hyperparathyroidism (PHPT), which is less common in adolescents. We first reported a spontaneous unilateral rupture in a young patient with PHPT.

Atypical skeletal manifestations of rickets in a familial hypocalciuric hypercalcemia patient

Familial hypocalciuric hypercalcemia (FHH) is caused by inactivating mutations in the calcium-sensing receptor (CaSR) gene. The loss of function of CaSR presents with rickets as the predominant skeletal abnormality in mice, but is rarely reported in humans. Here we report a case of a 16-year-old boy with FHH who presented with skeletal manifestations of rickets. To identify the possible pathogenic mutation, the patient was evaluated clinically, biochemically, and radiographically. The patient and his family members were screened for genetic mutations. Physical examination revealed a pigeon breast deformity and X-ray examinations showed epiphyseal broadening, both of which indicate rickets. Biochemical tests also showed increased parathyroid hormone (PTH), 1,25-dihydroxyvitamin D, and elevated ionized calcium. Based on these results, a diagnosis of FHH was suspected. Sequence analysis of the patient’s CaSR gene revealed a new missense mutation (c.2279T>A) in exon 7, leading to the damaging amino change (p.I760N) in the mature CaSR protein, confirming the diagnosis of FHH. Moreover, the skeletal abnormities may be related to but not limited to vitamin D abnormity. Elevated PTH levels and a rapid skeletal growth period in adolescence may have also contributed. Our study revealed that rickets-like features have a tendency to present atypically in FHH patients who have a mild vitamin D deficiency, and that CaSR mutations may have a partial role in the pathogenesis of skeletal deformities.

Primary hyperparathyroidism may masquerade as rickets-osteomalacia in vitamin D replete children

Primary hyperparathyroidism, typically a disease of the middle aged and the old, is less commonly seen in children. In children the disease has a bimodal age distribution with calcium sensing receptor mutation presenting in infancy as hypercalcemic crises and parathyroid adenoma or hyperplasia presenting later in childhood with bone disease. The childhood parathyroid adenomas are often familial with multiglandular disease and manifest with severe bone disease unlike adults. We report a series of four male patients with juvenile primary hyperparathyroidism, three of whom presented with bone disease masquerading as rickets-osteomalacia. One patient had asymptomatic hypercalcemia with short stature. Parathyroid adenoma was detected in all the four cases and all of them underwent resection of parathyroid adenomas confirmed on histopathology. Post-surgery all the cases had initial hypocalcaemia followed by normocalcemia. One case developed pancreatitis after surgery even after achieving normocalcemia. We conclude that parathyroid adenomas, although uncommon in children, are an important cause of skeletal disease that may initially be confused with hypovitaminosis D.