[Importance of ultrasonic diagnosis for adequate resection in benign and malignant goiter].

In the Basel area, with a considerable prevalence of benign uni- and multinodular goiter, the diagnosis or exclusion of malignant goiter is often difficult. A frequent result is unnecessary hemithyroidectomy for benign nodules, and delayed and inadequate surgery inasmuch as 25% of patients with a malignancy. The diagnostic contribution of ultrasonography was investigated prospectively in a consecutive series of 162 patients referred to a surgical unit. No surgical indication was found in 42 subjects in whom the clinical finding of small benign goiter was confirmed by ultrasonography. In the remaining patients the diagnostic procedure proved rather accurate in ruling out malignancy: in uni- and multinodular goiter the specificity was 94% and 80% respectively; the specificity of the diagnostic signs of benignity was 92% and 98% respectively. Sensitivity in detecting malignant goiter and atypical adenoma was 79% in uninodular and 73% in multinodular goiter. The frequent occurrence of a benign, nonhypercellular hypoechogenic structure (such as fibrosis, small cystic lesions, coloid cyst) results in low sensitivity (40%) for this sonographic sign in multinodular goiter, whereas in uninodular goiter the sensitivity of the sign was 85%. In 2 out of 16 patients (16%) with malignant goiter hemithyroidectomy was missed as the minimal primary procedure.