Transformación anaplásica tardía de dos bocios multinodulares

Anaplastic thyroid carcinoma is a highly aggressive tumor with a mean survival of 3-7 months. Up to one half of patients have long-standing multinodular goiter and 20-30% have a coexisting differentiated carcinoma. We present two elderly patients under follow-up for multinodular goiters that suddenly showed anaplastic transformation many years after the initial diagnosis. Given the possibility of malignant transformation and the fatal prognosis of this carcinoma, life-long surveillance of these patients is advisable.