Proximal myopathy due to a giant parathyroid adenoma

Parathyroid adenomas are the commonest cause of primary hyperparathyroidism, and can have varied systemic manifestations. Presentation as predominant proximal myopathy is uncommon. Most parathyroid adenomas are <1 g in weight, and those >3.5 g are called giant parathyroid adenomas and are rare. We report a patient presenting with long-standing severe muscle weakness and wasting, initially suspected to have a neuromuscular cause, who was later diagnosed to have a parathyroid adenoma. He also had clubbing—an uncommon manifestation of hyperparathyroidism. Surgical exploration revealed a giant parathyroid adenoma of the right superior gland, 3.5×2.4×1.8 cm, weighing 5.5 g, which was excised. He had an uneventful postoperative course with parathormone levels dropping from 688 to 4.1 pg/ml. On follow-up, he regained muscle strength progressively and has resumed his job. Parathyroid adenoma has to be kept in mind as a rare but potentially treatable cause of neuromyopathic conditions.