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| CASE REPORT |
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| Year : 2022 | Volume
: 12
| Issue : 1 | Page : 41-44 |
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Sporadic primary hyperparathyroidism mimicking rickets in a child: A diagnostic challenge
MA Mujeeb Afzal, Vivek Kyatham, P Srinivas Rao, Vijay Sheker R Danda
Department of Endocrinology, Gandhi Medical College and Hospital, Secunderabad, Hyderabad, Telangana, India
| Date of Submission | 01-Jun-2021 |
| Date of Decision | 13-Apr-2022 |
| Date of Acceptance | 06-May-2022 |
| Date of Web Publication | 02-Sep-2022 |
Correspondence Address:
Vijay Sheker R Danda
Department of Endocrinology, Gandhi Medical College and Hospital, Musheerabad, Secunderabad 500003, Hyderabad, Telangana
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/ajem.ajem_6_21
Primary hyperparathyroidism (PHPT) is very rare in children and adolescents. Here, we report a case of a 9-year-old boy with PHPT who presented with skeletal manifestations of rickets. Biochemical investigations initially revealed vitamin D deficiency. Re-evaluation due to the lack of clinical improvement following vitamin D supplementation revealed hypercalcemia and elevated parathyroid hormone. 99mTc-sestamibi scan found a right inferior parathyroid adenoma, and genetic analysis did not find any pathogenic variant. The excision of parathyroid adenoma led to the resolution of all clinical features. In a child with rickets, the absence of resolution of clinical features after vitamin D supplementation and hypercalcemia at presentation, or after vitamin D supplementation, needs further evaluation to rule out PHPT. Keywords: Primary hyperparathyroidism, rickets, vitamin D deficiency
How to cite this article:
Mujeeb Afzal M A, Kyatham V, Srinivas Rao P, Danda VS. Sporadic primary hyperparathyroidism mimicking rickets in a child: A diagnostic challenge. Afr J Endocrinol Metab 2022;12:41-4 |
How to cite this URL:
Mujeeb Afzal M A, Kyatham V, Srinivas Rao P, Danda VS. Sporadic primary hyperparathyroidism mimicking rickets in a child: A diagnostic challenge. Afr J Endocrinol Metab [serial online] 2022 [cited 2023 Jun 10];12:41-4. Available from: http://www.ajemjournal.org/text.asp?2022/12/1/41/355336 |
| Introduction | |  |
Primary hyperparathyroidism (PHPT) typically occurs in the fifth and sixth decades of life, especially in postmenopausal women. It is extremely uncommon among children with an incidence estimated at only 2–5 in 100,000.[1] Pediatric cases of PHPT can present as asymptomatic hypercalcemia or its complications (nephrolithiasis, fractures, and acute pancreatitis), with multiglandular involvement or associated genetic syndromes.[2],[3] Rickets as the presenting feature of PHPT in children is extremely rare with only 26 cases reported till date.[4] Here, we report a case of a 9-year-old boy presenting with typical features of rickets, diagnosed to have PHPT due to a right inferior parathyroid adenoma, and who showed resolution of all clinical features following parathyroidectomy.
| Case history | | |
A 9-year-old male child presented with short stature, progressively worsening leg deformities and gait abnormality, of 2-year duration. The child experienced bone pain and proximal muscle weakness and had limited physical activities. There was no history of trauma, bone fractures, polyuria, fatigue, irritability renal stones, or neck swelling. Birth and developmental milestones along with dentition were appropriate for age. There was no family history of similar complaints.
The patient had a significant short stature with actual height of 117 cm (standard deviation score: −2.3), widening of wrists, and genu valgus [Figure 1]. There was no palpable mass in the neck on physical examination. Skeletal radiography showed widening of the distal ends of the long bones (radius, ulna, femur, and tibia) along with irregular metaphyseal margins [Figure 2], with bone age of 8 years. Biochemical investigations initially revealed serum calcium of 8.7 mg/dL, corrected calcium of 8.86 mg/dL (serum albumin of 3.8 g/dL), serum phosphate of 2.4 mg/dL, and vitamin D of 7.34 ng/mL. He was treated with weekly sachets of 60000 U of cholecalciferol for 6 weeks by a family physician. As there was no improvement in the bone pain, he was re-evaluated, which revealed hypercalcemia, hypophosphatemia, and markedly elevated alkaline phosphatase (ALP) and high intact parathyroid hormone (iPTH) levels. Results of biochemical evaluation are shown in [Table 1]. Clinical, biochemical, and radiological evaluation suggested the diagnosis of rickets with hyperparathyroidism.  | Figure 2: X-ray bilateral knee demonstrates epiphyseal widening and metaphyseal marginal irregularity of bilateral tibial condyles
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Ultrasonography of the neck showed 1.5 × 0.6 cm well-defined hypoechoic lesion suggestive of a parathyroid adenoma. Tc99m-sestamibi scan revealed abnormally increased tracer uptake (>2 cm) in early images near the lower pole of thyroid and retention in delayed images suggestive of the right inferior parathyroid adenoma [Figure 3]. Multiglandular endocrine neoplasia (MEN) workup was negative. Clinical exome analysis by next-generation sequencing revealed no clinically significant variant. | Figure 3: Tc99-sestamibi parathyroid scintigraphy findings: early image shows an abnormal increased tracer uptake in a vertically ovoid focus (more than 2 cm) in proximity to the right lower pole of thyroid and delayed scan shows the complete washout of tracer from the left lobe of thyroid and retention of tracer in the right inferior focus suggestive of a right inferior parathyroid adenoma
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The patient underwent right inferior parathyroidectomy. After removal of parathyroid adenoma, iPTH levels at 5 min and 10 min were 190 pg/mL and 60 pg/mL suggestive of successful removal. On postoperative day 3, the patient developed both clinical and biochemical hypocalcemia and was started on calcium and calcitriol. He required low-dose calcium carbonate supplements for 2 months, and on follow-up over next 6 months, he had improvement in limb deformity with normal biochemical profile.
| Discussion | | |
PHPT is much less common in children and adolescents, but has greater morbidity in this age group, as most young patients with PHPT will have asymptomatic hypercalcemia or its complications. Rickets as the presenting feature of PHPT in children is extremely rare. PHPT can present with skeletal manifestation of rickets, which leads to misdiagnosis and delay in treatment.[3],[4]
In a review of 16 PHPT cases presenting with rickets, genu valgus was found to be the most common presenting feature (75%), followed by rachitic rosary (50%), bone pain (37.5%), and wrist widening (31.25%).[5] Our case had radiological findings consistent with rickets. Typical radiological features associated with PHPT such as subperiosteal resorption, brown tumors, pathological fractures, and osteitis fibrosa cystica were not seen. It can be speculated that the severe skeletal abnormalities may be due to both vitamin D deficiency and deleterious effect of elevated PTH. Thirteen of the children in the review had hypercalcemia and hypophosphatemia at presentation, whereas three cases had normocalcemia at presentation, but later developed hypercalcemia after correction of vitamin D deficiency, like in our case.
PHPT in India is believed to be associated with a larger parathyroid adenoma size and more severe bone disease, and as many as 50% of patients do not have hypercalcemia at initial presentation due to co-existing vitamin D deficiency.[6] PHPT in our patient was due to parathyroid adenoma, similar to the review by Pitukcheewanont et al.[5] in which 13 out of 14 children had adenoma and only one child had multiglandular disease.
The lack of sun exposure and nutritional deficiency may explain the development of acquired vitamin D deficiency. In spite of being a tropical country, hypovitaminosis D is extremely common among school children in India with a reported prevalence of 85%–95%.[7] The lack of clinical improvement following vitamin D supplementation in our case was due to the deleterious effect of persistently elevated PTH on chondrocytes and bone.
An important feature of PHPT in younger patients is the relatively high prevalence of germline inactivating mutations of the CASR gene, which encodes the calcium-sensing receptor. PHPT in children can also be due to an autosomal-dominant disorder characterized by multiple gland hyperplasia, associated with MEN-1, hyperparathyroidism-jaw tumor syndrome, or very rarely with MEN-2.[6] These disorders can have multiple gland involvement, making the genetic analysis important prior to the surgery. The literature is sparse regarding genetic evaluation in cases of PHPT presenting with rickets. Our case had no mutation found on next-generation sequencing.
The parathyroid surgery has evolved over the years because of the development of preoperative localization techniques and rapid intraoperative parathyroid hormone (IOPTH) assay. The success of this approach is based on the fact that PTH has a half-life of 5 min. A drop in IOPTH levels of >50% from the baseline at 10 min after gland excision suggests that all abnormal glands had been removed.[8] The surgical removal of a parathyroid adenoma led to bone healing and normalization of blood chemistry.
This case report highlights that rickets can rarely be the presenting feature of PHPT. In a child with rickets, the absence of resolution of clinical features after vitamin D supplementation, hypercalcemia at presentation, or its occurrence following vitamin D supplementation needs further evaluation to rule out PHPT. Early diagnosis in these cases is important as the availability of curative surgical therapy helps in preventing deformities and improving the quality of life.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Acknowledgment
None.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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| 5. | Pitukcheewanont P, Numbenjapon N, Costin G Ectopic thymic parathyroid adenoma and vitamin D deficiency rickets: A 5-year-follow-up case report and review of literature. Bone 2008;42:819-24. |
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| 7. | Marwaha RK, Tandon N, Reddy DR, Aggarwal R, Singh R, Sawhney RC, et al. Vitamin D and bone mineral density status of healthy school children in northern India. Am J Clin Nutr 2005;82:477-82. |
| 8. | Irvin GL 3rd, Dembrow VD, Prudhomme DL Operative monitoring of parathyroid gland hyperfunction. Am J Surg 1991;162:299-302. |
[Figure 1], [Figure 2], [Figure 3]
[Table 1]
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