Primary hyperthyroidism due to a parathyroid adenoma with subsequent myasthenia gravis.
Sir,

There are two cases in the world literature reporting an association between myasthenia gravis with thymoma and hyperparathyroidism.1,,2 In the first, the hyperparathyroidism was due to a parathyroid adenoma,1 while in the second it was due to nodular hyperplasia.2 Subsequently, a case with no myasthenia gravis but with a thymoma and hyperparathyroidism due to a parathyroid adenoma has been published.3

We report a case of myasthenia gravis and hyperparathyroidism due to parathyroid adenoma with no thymoma detected. We also raise the possibility that the myasthenia gravis was precipitated by the use of intravenous pamidronate.

A 67‐year‐old lady, previously treated for thyrotoxicosis with radioiodine, presented to the urologists with renal colic. Laboratory investigation revealed hypercalcaemia (3.13 mmol/l; normal range 2–2.6 mmol/l) and a high PTH level (320 ng/l; normal range 12–72 ng/l). At this time, the patient reported no other symptoms. TSH was within the laboratory reference range with the patient taking thyroxine 100 mcg daily.

Initial treatment of the hypercalcaemia was given with intravenous pamidronate (60 mg in 250 ml …