Microcalcifications and psammoma bodies in thyroid tumors.

Microcalcifications are a highly specific sign of malignancy being frequently detected in papillary or medullary cancers, while only 5% of nodular goiters and 3-4% of adenomas show this feature on thyroid sonogram. They correspond to clusters of psammoma bodies at cytological or histological examination. The microphotographs of cytological smears show psammoma bodies as 50 to 70 < m round-shaped calcific concretions with a glassy appearance, concentrically laminated.