Hyperparathyroidism is a common endocrine disorder usually cured when treated surgically. Parathyroid gland overactivity documented by appropriate laboratory studies may be associated with general hyperplasia of the parathyroid glands or with an adenoma involving one or more parathyroid glands. Kidney stones, osteopenia/osteoporosis, gastrinoma, recurrent pancreatitis, and other conditions are some of the clinical disorders that imply a disorder of the parathyroid glands. Hypercalcemia is discovered as a result of more frequent calcium determinations performed as part of a general screening survey. Hyperparathyroidism is associated with gastrinoma in approximately one-third of patients with the familial multiple endocrine neoplasia type I (MEN I) syndrome. A mitogenic cause for the relatively high incidence of recurrent hyperparathyroidism in the familial MEN I syndrome suggests the need for a radical approach, which may consist of total parathyroidectomy with parathyroid autotransplantation into the muscle in the nondominant forearm versus removal of three and a half parathyroid glands.
Evidence of hyperparathyroidism associated with hypercalcemia of 12 mg/dL after renal transplantation may be an indication to consider a radical parathyroidectomy. Hypercalcemia and extremely high parathyroid hormone (PTH) values may occur after renal transplantation.
Parathyroidectomy should precede surgical procedures for gastrinoma in patients with MEN I syndrome. There is an apparent increase in supernumerary parathyroid glands in those with familial MEN I syndrome, which suggests the need to remove the thymus, where an accessory parathyroid gland may be located when the cervical exploration is negative. More rarely, thyroidectomy also may be considered in a valiant search for a parathyroid gland buried within the thyroid gland if a parathyroid is not visible under the thyroid capsule. The presence of one endocrine tumor suggests the desirability of a general search for other endocrine tumors, such as gastrinoma, pheochromocytoma, prolactinoma, and others, before parathyroidectomy is performed.
Recurrence of hyperparathyroidism after a parathyroidectomy requires a review of previous surgical procedures and a review of the pathologist’s report on the parathyroid glands. Were the usual four glands found, and where were they? Were any glands verified in the thyroid, thymus, anterior or posterior mediastinum, or above the thyroid? Which glands were removed or verified by frozen-section examination? Every effort should be made to localize the parathyroid glands prior to any reoperation. Four-dimensional computed tomography, magnetic resonance imaging, radionuclide (sestamibi), and ultrasound scans may be useful. However, selective venous sampling with hormonal assays may be necessary if the abnormal parathyroid gland cannot be identified by these means.
The surgeon should be familiar with the usual locations of the parathyroid glands as well as their common areas of migration (FIGURE 1). Rarely, an adenoma of the parathyroid is large enough to be palpable. A number of procedures may be used to localize the adenoma, including ultrasound at 10 MHz as well as radionuclide imaging with sestamibi. Cross-sectional imaging with four-dimensional computed tomography and magnetic resonance imaging ...