Normocalcemic primary hyperparathyroidism

Abstract

Normocalcemic primary hyperparathyroidism (PHPT) is a newer phenotype of PHPT defined by elevated PTH concentrations in the setting of normal serum calcium levels. It is increasingly being diagnosed in the setting of evaluation for nephrolithiasis or metabolic bone diseases. It is important to demonstrate that PTH values remain consistently elevated and to measure ionized calcium levels to make the diagnosis. A diagnosis of normocalcemic disease is one of exclusion of secondary forms of hyperparathyroidism, including vitamin D deficiency, renal failure, medications, malabsorption, and hypercalciuria. Lack of rigorous diagnostic criteria and selection bias of the studied populations may explain the different rates of bone and renal complications. The natural history still remains unknown. Caution should be used in recommending surgery, unless clearly indicated. Here we will review the diagnostic features, epidemiology, clinical presentation, natural history, medical and surgical management of normocalcemic PHPT.

Sporadic parathyroid adenoma: an updated review of molecular genetics

“…In cases of symptomatic disease, musculoskeletal, urinary, gastrointestinal, neural, and cardiovascular systems are affected. Surgical treatment is the only curative treatment and is indicated in cases of symptomatic disease and in asymptomatic if at least one of these conditions is fulfilled: (a) age <50 years old; (b) serum Ca >1 mg/dl (>0.25 mmol/L); (c) T-score below -2.5 in one of the following bone regions: lumbar spine, total hip, femoral neck, or 1/3 distal radius bone or detection of asymptomatic vertebral fracture by any imaging method; (d) creatinine clearance <60 cc/min; (e) 24-h urine calcium >300 mg/d (<10 mmol/d) together with increased risk of kidney stones based on biochemical stone risk analysis, presence of asymptomatic nephrolithiasis, or nephrocalcinosis detected by imaging methods ( 1 – 4 ).…”