PROBLEMS IN DIAGNOSIS AND MANAGEMENT OF FUNCTIONING PARATHYROID TUMORS

• The clinical symptoms of hyperparathyroidism may be obscure and varied, and the casual determination of serum calcium and phosphate levels may not suffice to establish the diagnosis. In one illustrative case only a persistently low serum phosphate level was demonstrable over several years of observation, and in another the serum calcium level varied between normal and elevated within a short space of time. These and other findings suggest that parathyroid hormone secretion may be intermittent and that the individual chemical response may be variable. Of the additional diagnostic tests employed, determination of renal phosphate reabsorption and the phosphatedeprivation test proved to be of value, while the calcium infusion test was misleading in several instances. In one patient with clinically typical hyperparathyroidism, normal parathyroid structures were observed in relation to the thyroid gland, but aberrant parathyroid tissue was found in the fat removed from the area behind the junction of the right and left innominate veins, emphasizing the need for anatomic dissection, removal, and histological examination of all fat tissue about the great vessels. The operative field must be kept absolutely bloodless as a requisite for identifying small masses of parathyroid tissue by their color. In one patient this led to the discovery of an intrathyroid parathyroid adenoma measuring 16 by 7 mm. In planning the surgery the patient should be forewarned that exploration of the mediastinum may be necessary.