Primary hyperparathyroidism from a probable ectopic parathyroid adenoma with severe skeletal disease and vitamin D deficiency.

Primary hyperparathyroidism (PHPT) may lead to skeletal deformities, fractures and renal failure in symptomatic patients if untreated. We present a case of a 30-year-old woman presented with muscle weakness, weight loss, hypercalcaemia and a pathological fracture, eventually with rapidly progressive musculoskeletal disease. Subsequent biochemical, radiographic and scintigraphy findings were consistent with PHPT from an ectopic mediastinal adenoma, and concomitant vitamin D deficiency. The severe hypercalcaemia was adequately temporised with hydration, forced diuresis and intravenous bisphosphonates. Removal of the adenoma by video-assisted thoracoscopic surgery was contemplated; however, consent was withdrawn precluding histological confirmation. A review of literature shows the changing profiles of patients with PHPT, the uncommon occurrence of parathyroid adenomas in ectopic locations and possible association between severity of PHPT and vitamin D status.