Maria Cristina Chammas MD, Presenter: Nothing to Disclose

Raquel Moyses, Abstract Co-Author: Nothing to Disclose

Vergilius Araujo Filho, Abstract Co-Author: Nothing to Disclose

Grace Mulatti, Abstract Co-Author: Nothing to Disclose

Marilia Brescia MD, Abstract Co-Author: Nothing to Disclose

Giovanni Guido Cerri MD, PhD, Abstract Co-Author: Nothing to Disclose

Ultrasonography (US) is, nowadays, the most used and sensitive method for identification of thyroid nodules. Less than 10 % of them are malignant. The aim of this study is to determine the predictive value of malignancy of microcalcifications determined by US in the thyroid nodules

One hundred and seventy-four patients from the “Hospital das Clínicas” of the University of São Paulo Medical School, were prospectively studied between January 1997 and March 2001. Methods: The 177 nodules were studied by US then compared to their fine needle aspirative biopsy (FNAB). Microcalcifications were defined as fine punctate calcifications, that measured less than or equal to (≤) 2mm in diameter, with or without a posterior acoustic shadow and without comet tail sign. The association between the presence and type of calcification and cytology findings was verified through the chi-square test or likelihood ratio; p< 0,05 was considered significant.

The cytologic analysis showed that 136 nodules (76,84%) were benign, 19 (10,73%) were indetermined, 9 (5,08%) were suspicious for malignancy and 13 (7,34%) were malignant. Thirty nodules of 177 showed calcification, of which 17 (56,66%) had fine calcifications, 3 (10%) fine and gross calcifications and 10 (33,33%) only gross calcification. Seven (41.18%) of 17 fine calcified nodules were malignant on cytology, 8 (47.06%) were benign, 1 (5,88%) was indetermined and 1 suspect of malignancy. We found statistical significance between the presence of fine calcifications and malignancy (p=0.001) and, in the 13 malignant nodule group, 8 (61.50%) had fine calcifications.

This study suggests that microcalcifications were highly specific for malignancy and are present in 60% of the malignant nodules.

The microcalcification is highly specific of malignancy in thyroid nodules. This signal must be identify on US scan as it was proposed, and it can be considered to select the nodules to FNAB.

Chammas, M, Moyses, R, Araujo Filho, V, Mulatti, G, Brescia, M, Cerri, G, Predictive Value of Malignancy in the Finding of Microcalcifications on Ultrasonography of Thyroid Nodules.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5016469.html