Evaluation of routine basal serum calcitonin measurement for early diagnosis of medullary thyroid carcinoma in seven hundred seventy-three patients with nodular goiter. - Ozgen,A.G.; Hamulu,F.; Bayraktar,F.; Yilmaz,C.; Tuzun,M.; Yetkin,E.; Tuncyurek,M.; Kabalak,T. (Thyroid, 1999)