Endocrine Abstracts

A 34-year-old lady with previous renal stones, constipation and well controlled bipolar mood disorder, on lithium for 13 years, was referred with a high calcium of 2.75 mmol/l (normal range: 2.10–2.58 mmol/l) and raised parathyroid hormone of 9.1 pmol/l (normal range: 1.1–4.2 pmol/l). Urine calcium excretion and TFT were normal.

The biochemistry was consistent with primary hyperparathyroidism. A workup for possible underlying MEN syndrome came back as negative. An ultrasound scan of the parathyroid showed three tiny soft tissue hypoechoic nodules inferior to the lower pole of the left lobe of thyroid, raising a suspicion of parathyroid adenomas. However, a sestamibi scan was unable to localise any parathyroid adenoma. She underwent a bilateral neck exploration and four gland parathyroidectomy and thymectomy as a fifth parathyroid gland was felt to be embedded within the thymus. Four days post operatively, she was admitted with confusion, tachycardia and carpo-pedal spasm. She was hypocalcemic (Ca:1.93 mmol/l) which was treated with Sandocal and alfacalcidol. TFT revealed a thyrotoxic picture with free T₄ >100 pmol/l, free T₃ of 50 pmol/l and TSH <0.02 mU/l. This raised a suspicion of possible surgery induced thyroiditis caused by handling of the thyroid during surgery. She was treated with propylthiouracil, propranolol along with antibiotics to cover for possible surgical site infection. TFTs improved dramatically and normalized in about 3 weeks. Propylthiouracil dose was tapered and stopped within few weeks.

Although post-operative thyroiditis is well described, it is under recognised. Manipulation of the thyroid gland either during neck exploratory surgery or repeated palpation can result in inflammation of the thyroid gland. Hyperthyroidism is usually transient due to leakage of the preformed thyroid hormone in blood. Careful attention to the thyroid test should be paid in the post-operative period following surgical procedures in which thyroid gland has been manipulated.