The Classical Tetrad Revisited: Bones, Stones, Groans, and Moans as the Unifying Presentation of Severe Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is the commonest cause of hypercalcaemia in the ambulatory setting. While asymptomatic disease now predominates in Western populations owing to routine biochemical screening, the full classical symptomatic phenotype — constituting the tetrad of bones (osteitis fibrosa cystica), stones (nephrocalcinosis and hypercalciuria), groans (recurrent pancreatitis and gastrointestinal dysmotility), and moans (nephrogenic diabetes insipidus with florid polyuria and constitutional symptoms) — remains the predominant mode of presentation in South Asian settings. We present the case of a 41-year-old male photographer from Tirunelveli who sustained a one-year diagnostic delay during which recurrent upper abdominal pain was repeatedly managed as idiopathic acute pancreatitis without a serum calcium measurement. Biochemical evaluation ultimately revealed severe hypercalcaemia (peak serum calcium 14.1 mg/dL), an intact parathyroid hormone (iPTH) exceeding 2500 pg/mL — approximately 38-fold above the upper limit of normal — hypercalciuria (24-hour urinary calcium 300 mg/day), and a massively elevated bone-turnover marker (alkaline phosphatase 1454 IU/L with normal transaminases). Skeletal radiographs confirmed the salt-and-pepper calvarium of osteitis fibrosa cystica and pathognomonic subperiosteal bone resorption of the radial phalangeal cortex bilaterally. Abdominal ultrasonography demonstrated an atrophic pancreas with intraparenchymal calcifications consistent with chronic calcific pancreatitis. Tc-99m sestamibi parathyroid scintigraphy localised a right upper parathyroid adenoma, concordant with neck ultrasonography. The patient was managed with aggressive intravenous isotonic saline hydration followed by loop diuretic therapy, and was planned for right upper parathyroidectomy with pre-operative active vitamin D and calcium supplementation to mitigate the anticipated risk of post-operative hungry bone syndrome. This case underscores that serum calcium must be measured in every patient with recurrent pancreatitis of undetermined aetiology, and that the mnemonic "bones, stones, groans, and moans" retains full clinical relevance as a prompt to suspect primary hyperparathyroidism in patients with unexplained multi-system disease.