[Multiple endocrine type 2 neoplasia in 3 families]

In the last 15 years, 29 subjects (13 males, 16 females) aged 8-69 years, belonging to 3 kindreds with multiple endocrine neoplasia type 2 (MEN-2) were studied with rapid i.v. calcium gluconate infusions (2 mg Ca++/kg in 1 minute) in order to detect the presence of medullary thyroid cancer (MTC). Serum samples were obtained at 0, 2, 5, 7 and 10 minutes. Calcitonin was measured by radioimmunoassay using a commercial kit. On the basis of the results obtained in a control group of 28 healthy volunteers, hypercalcitoninemia (HCT) was defined as basal and stimulated values above 100 and 200 pg/ml, respectively, in either sex. In 2 patients with nodular goiter, HCT correctly predicted the malignant nature of the lesions. Out of 22 clinically normal subjects, 3 had HCT: one refused consent for surgery, but in the remaining 2 MTC was found, without extraglandular extension. Seven patients with surgically proven MTC have been followed; 4 have shown HCT: 3 women refused permission for exploratory surgery, and a 46 year old male with enlarged lymph nodes in the neck was found to have metastatic papillary thyroid cancer. Both calcitonin and thyroglobulin were immunohistochemically discovered in metastases and the original thyroid tumor (differentiated thyroid cancer, intermediate type). There were 2 false negative tests in patients with metastatic disease. This type of biochemical screening in members of MEN-2 kindreds allows early detection of MTC and its prevention through thyroidectomy in a preneoplastic stage (C-cell hyperplasia).(ABSTRACT TRUNCATED AT 250 WORDS)