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.

Renal Tubular Acidosis Manifesting as Severe Metabolic Bone Disease.

Renal tubular acidosis (RTA) is a condition characterized by normal anion gap metabolic acidosis. Type 1 and type 2 RTA are the most common, and are caused by defective secretion of hydrogen ions and impaired absorption of bicarbonate, respectively. Long-standing uncorrected acidosis can lead to metabolic bone disease (MBD). Rickets and osteomalacia remain the commonest manifestations of uncorrected RTA. In addition, there can be a myriad of other skeletal manifestations like fractures, pseudofractures, secondary osteoporosis and even sclerotic bone disease. The postulated mechanism for bone involvement includes acidosis-mediated exaggerated osteoclastic bone resorption. Other contributory factors include abnormal renal handling of phosphate leading to hypophosphataemia in proximal RTA, and impaired vitamin D metabolism and action. In distal RTA, hypercalciuria and secondary hyperparathyroidism may play a key role for bone involvement. Recognizing the disease in its early course is important to prevent permanent sequelae of skeletal involvement. Most of these patients may, in fact, undergo orthopaedic interventions without primary correction of acidosis. We describe five cases who presented with MBD in varied forms. While evaluating the aetiology of MBD, they were diagnosed with RTA. Subsequently, we attempted to analyse the causes of RTA. Although the common causes were ruled out, genetic aetiology could not be ascertained due to resource constraints. RTA remains an important differential diagnosis of MBD. More awareness is required to diagnose the disease early and to treat it adequately. Our case series is an attempt to provide the clinical, biochemical and skeletal spectrum of RTA. In addition, we have attempted to provide algorithms for the approach and evaluation of RTA along with their varied causes.