Parathyroid pathology in an intrathyroidal position.
A systematic approach based on the embryology of the parathyroid glands should allow for the appropriate identification of both normal and abnormal glands at the time of parathyroidectomy. The exact role of subtotal thyroidectomy as part of this approach remains in question because of the low incidence of intrathyroidal adenomas reported in the past. From 1978 to 1992, 97 cervical explorations were performed in 96 patients (mean age: 56 years) with hyperparathyroidism. Four patients (4%) were found to have intrathyroidal parathyroid adenomas and were cured by ipsilateral partial or subtotal thyroid lobectomy on the side of a missing gland. One parathyroid adenoma completely replaced the right lobe of the thyroid, whereas two inferior and one superior intrathyroidal adenomas were found in the remaining three patients. The 4% incidence of intrathyroidal adenomas is higher than that reported in most series and suggests that this entity may be a more common cause of failed parathyroid explorations than is currently thought. Ipsilateral thyrotomy or subtotal thyroid lobectomy continues to be a potentially curative procedure for hyperparathyroidism when there is a missing and presumably diseased superior or inferior gland.