Parathyroid sonography: diagnostic accuracy related to shape, location, and texture of the gland.

The sonographic features of 51 pathological parathyroid glands detected pre-operatively were analysed. Atypical texture was found in 23.5% and variation in shape in 15.6% of the cases. Cystic parathyroid glands are difficult to differentiate from thyroid cysts, and may be the cause of false positive diagnosis, as in three cases in this series. Topographic assessment showed a relatively low sensitivity in detecting disease in the right upper gland (50%) and in the upper mediastinum (70%). The decreased accuracy in these regions is probably because of the particular anatomical location of the right upper gland and sonographic limitations in screening the mediastinal region. Awareness by the radiologist and surgeon of the variations in texture and location may influence both diagnosis and intraoperative detection of the abnormal parathyroid gland.