Results of a screening program for multiple endocrine neoplasia type II.

After the diagnosis of MEN IIa syndrome in five members of a British family, a further 180 members were identified, 167 of whom were still alive. From death certificates, a further three were found to have been affected. Of these eight patients, only two were diagnosed and survived. Over the next four years, these two survivors and 90 others (those over the age of ten years) attended a screening program using alcohol or pentagastrin stimulated plasma calcitonin for MCT or urinary catecholamines for pheochromocytoma. The two surviving patients and 12 others were thought to have abnormal screening tests. One patient with an abnormal catecholamine excretion level had bilateral pheochromocytomas removed. Of the 13 patients with abnormal stimulated plasma calcitonin levels, five underwent total thyroidectomy, but MCT was found in only two. One of these patients and two of those in whom no tumor was found had persistently elevated stimulated plasma calcitonin levels postoperatively, suggesting the presence of C cells and, thus, persisting risk of MCT. In all patients, plasma calcitonin concentrations were variable, and an established normal range of values is essential if unnecessary surgical treatment is to be avoided. Pheochromocytoma proved difficult to diagnose, and pentagastrin stimulated plasma catecholamines deserves evaluation as a screening test. Despite the large effort involved, permanent screening of all family members is recommended as the only means of reducing mortality. Following any treatment, screening should continue because new disease or recurrence is possible.