Image-guided fine needle biopsy of Fasl mandibular lymph nodes.

<p><b>A.</b> Transverse section of a Fasl mouse neck imaged with HF US. The enlarged cervical mandibular node is evident as an oval hypoechoic region near the skin surface (circumscribed in yellow). Scale bar = 1 mm. <b>B.</b> Frames from fine needle biopsy of a Fasl mandibular node guided by HF US. Images show the position of the sampling hyperechoic needle tip prior to cervical skin penetration (<i>left</i>), position of the needle during tissue removal (<i>middle</i>), and following needle withdrawal (<i>right</i>). Note the break in the skin following needle withdrawal (arrow). The angle and trajectory of the dorsal needle surface is denoted by the yellow dotted line. Scale bar = 1 mm. The entire procedure is shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100185#pone.0100185.s003" target="_blank">Video S1</a>. <b>C.</b> Examples of lymph tissue obtained by HF US guided FNA of a Fasl cervical mandibular node following staining and processing by cytospin. Scale bar = 100 µm. LT; lymph tissue, RF; reticular fibers, L; individual lymphocytes.