Sonographic guidance in diagnosing anterior mediastinal mass: Importance of visualizing internal mammary vessels

Percutaneous needle aspiration biopsy (PNAB) of thoracic lesions has become a frequently performed procedure in interventional radiology. Fluoroscopy is adequate to guide the needle into large masses or masses outlined by contrast medium. More recently, when computed tomography (CT) scanning or high resolution ultrasonography is used, even lesions smaller than 1 cm can be biopsied.' Since normal vascular structures can be visualized with contrast-enhanced CT, mediastinal and perivascular lesions are amenable to PNAB. Using ultrasound guidance, aspiration biopsies of peripheral chest lesions have been perf ~ r r n e d ~ , ~ including, in a few cases, mediastinal m a s s e ~ . ~ ~ However, no publication has ever mentioned the possibility of internal mammary artery detection by Doppler sonography before ultrasonically guided mediastinal puncture. Furthermore, 2 cases of life-threatening hemorrhage due to bleeding from this vessel after X-ray PNAB have recently been r e p ~ r t e d . ~ We report one case of a right parasternal, anterior mediastinal mass with sonographically guided aspiration biopsy after visualization of the adjacent vascular structures, especially internal mammary vessels.